Ionic.Zip.Partial

The ZipFile type represents a zip archive file. This is the main type in the DotNetZip class library. This class reads and writes zip files, as defined in the format for zip described by PKWare. The compression for this implementation is provided by a managed-code version of Zlib, included with DotNetZip in the classes in the Ionic.Zlib namespace.

Returns true if an entry by the given name exists in the ZipFile.

The default text encoding used in zip archives. It is numeric 437, also known as IBM437.

Provides a string representation of the instance.

a string representation of the instance.

Creates a new ZipFile instance, using the specified filename.

Applications can use this constructor to create a new ZipFile for writing, or to slurp in an existing zip archive for read and update purposes. To create a new zip archive, an application can call this constructor, passing the name of a file that does not exist. The name may be a fully qualified path. Then the application can add directories or files to the ZipFile via AddDirectory(), AddFile(), AddItem() and then write the zip archive to the disk by calling Save(). The zip file is not actually opened and written to the disk until the application calls ZipFile.Save(). At that point the new zip file with the given name is created. If you won't know the name of the Zipfile until the time you call ZipFile.Save(), or if you plan to save to a stream (which has no name), then you should use the no-argument constructor. The application can also call this constructor to read an existing zip archive. passing the name of a valid zip file that does exist. But, it's better form to use the static method, passing the name of the zip file, because using ZipFile.Read() in your code communicates very clearly what you are doing. In either case, the file is then read into the ZipFile instance. The app can then enumerate the entries or can modify the zip file, for example adding entries, removing entries, changing comments, and so on. One advantage to this parameterized constructor: it allows applications to use the same code to add items to a zip archive, regardless of whether the zip file exists. Instances of the ZipFile class are not multi-thread safe. You may not party on a single instance with multiple threads. You may have multiple threads that each use a distinct ZipFile instance, or you can synchronize multi-thread access to a single instance. By the way, since DotNetZip is so easy to use, don't you think you should donate $5 or $10? Thrown if name refers to an existing file that is not a valid zip file. This example shows how to create a zipfile, and add a few files into it.


             String ZipFileToCreate = "archive1.zip";
             String DirectoryToZip  = "c:\\reports";
             using (ZipFile zip = new ZipFile())
             {
               // Store all files found in the top level directory, into the zip archive.
               String[] filenames = System.IO.Directory.GetFiles(DirectoryToZip);
               zip.AddFiles(filenames, "files");
               zip.Save(ZipFileToCreate);
             }


             Dim ZipFileToCreate As String = "archive1.zip"
             Dim DirectoryToZip As String = "c:\reports"
             Using zip As ZipFile = New ZipFile()
                 Dim filenames As String() = System.IO.Directory.GetFiles(DirectoryToZip)
                 zip.AddFiles(filenames, "files")
                 zip.Save(ZipFileToCreate)
             End Using

The filename to use for the new zip archive.

Creates a new ZipFile instance, using the specified name for the filename, and the specified Encoding.

See the documentation on the ZipFile constructor that accepts a single string argument for basic information on all the ZipFile constructors. The Encoding is used as the default alternate encoding for entries with filenames or comments that cannot be encoded with the IBM437 code page. This is equivalent to setting the property on the ZipFile instance after construction. Instances of the ZipFile class are not multi-thread safe. You may not party on a single instance with multiple threads. You may have multiple threads that each use a distinct ZipFile instance, or you can synchronize multi-thread access to a single instance. Thrown if name refers to an existing file that is not a valid zip file. The filename to use for the new zip archive. The Encoding is used as the default alternate encoding for entries with filenames or comments that cannot be encoded with the IBM437 code page.

Create a zip file, without specifying a target filename or stream to save to.

See the documentation on the ZipFile constructor that accepts a single string argument for basic information on all the ZipFile constructors. After instantiating with this constructor and adding entries to the archive, the application should call or to save to a file or a stream, respectively. The application can also set the property and then call the no-argument method. (This is the preferred approach for applications that use the library through COM interop.) If you call the no-argument method without having set the Name of the ZipFile, either through the parameterized constructor or through the explicit property , the Save() will throw, because there is no place to save the file. Instances of the ZipFile class are not multi-thread safe. You may have multiple threads that each use a distinct ZipFile instance, or you can synchronize multi-thread access to a single instance. This example creates a Zip archive called Backup.zip, containing all the files in the directory DirectoryToZip. Files within subdirectories are not zipped up.


             using (ZipFile zip = new ZipFile())
             {
               // Store all files found in the top level directory, into the zip archive.
               // note: this code does not recurse subdirectories!
               String[] filenames = System.IO.Directory.GetFiles(DirectoryToZip);
               zip.AddFiles(filenames, "files");
               zip.Save("Backup.zip");
             }


             Using zip As New ZipFile
                 ' Store all files found in the top level directory, into the zip archive.
                 ' note: this code does not recurse subdirectories!
                 Dim filenames As String() = System.IO.Directory.GetFiles(DirectoryToZip)
                 zip.AddFiles(filenames, "files")
                 zip.Save("Backup.zip")
             End Using

Create a zip file, specifying a text Encoding, but without specifying a target filename or stream to save to.

Creates a new ZipFile instance, using the specified name for the filename, and the specified status message writer.

See the documentation on the ZipFile constructor that accepts a single string argument for basic information on all the ZipFile constructors. This version of the constructor allows the caller to pass in a TextWriter, to which verbose messages will be written during extraction or creation of the zip archive. A console application may wish to pass System.Console.Out to get messages on the Console. A graphical or headless application may wish to capture the messages in a different TextWriter, for example, a StringWriter, and then display the messages in a TextBox, or generate an audit log of ZipFile operations. To encrypt the data for the files added to the ZipFile instance, set the Password property after creating the ZipFile instance. Instances of the ZipFile class are not multi-thread safe. You may not party on a single instance with multiple threads. You may have multiple threads that each use a distinct ZipFile instance, or you can synchronize multi-thread access to a single instance. Thrown if name refers to an existing file that is not a valid zip file.


             using (ZipFile zip = new ZipFile("Backup.zip", Console.Out))
             {
               // Store all files found in the top level directory, into the zip archive.
               // note: this code does not recurse subdirectories!
               // Status messages will be written to Console.Out
               String[] filenames = System.IO.Directory.GetFiles(DirectoryToZip);
               zip.AddFiles(filenames);
               zip.Save();
             }


             Using zip As New ZipFile("Backup.zip", Console.Out)
                 ' Store all files found in the top level directory, into the zip archive.
                 ' note: this code does not recurse subdirectories!
                 ' Status messages will be written to Console.Out
                 Dim filenames As String() = System.IO.Directory.GetFiles(DirectoryToZip)
                 zip.AddFiles(filenames)
                 zip.Save()
             End Using

The filename to use for the new zip archive. A TextWriter to use for writing verbose status messages.

Creates a new ZipFile instance, using the specified name for the filename, the specified status message writer, and the specified Encoding.

This constructor works like the ZipFile constructor that accepts a single string argument. See that reference for detail on what this constructor does. This version of the constructor allows the caller to pass in a TextWriter, and an Encoding. The TextWriter will collect verbose messages that are generated by the library during extraction or creation of the zip archive. A console application may wish to pass System.Console.Out to get messages on the Console. A graphical or headless application may wish to capture the messages in a different TextWriter, for example, a StringWriter, and then display the messages in a TextBox, or generate an audit log of ZipFile operations. The Encoding is used as the default alternate encoding for entries with filenames or comments that cannot be encoded with the IBM437 code page. This is a equivalent to setting the property on the ZipFile instance after construction. To encrypt the data for the files added to the ZipFile instance, set the Password property after creating the ZipFile instance. Instances of the ZipFile class are not multi-thread safe. You may not party on a single instance with multiple threads. You may have multiple threads that each use a distinct ZipFile instance, or you can synchronize multi-thread access to a single instance. Thrown if fileName refers to an existing file that is not a valid zip file. The filename to use for the new zip archive. A TextWriter to use for writing verbose status messages. The Encoding is used as the default alternate encoding for entries with filenames or comments that cannot be encoded with the IBM437 code page.

Initialize a ZipFile instance by reading in a zip file.

This method is primarily useful from COM Automation environments, when reading or extracting zip files. In COM, it is not possible to invoke parameterized constructors for a class. A COM Automation application can update a zip file by using the default (no argument) constructor, then calling Initialize() to read the contents of an on-disk zip archive into the ZipFile instance. .NET applications are encouraged to use the ZipFile.Read() methods for better clarity. the name of the existing zip file to read in.

Removes the given ZipEntry from the zip archive.

After calling RemoveEntry, the application must call Save to make the changes permanent. Thrown if the specified ZipEntry does not exist in the ZipFile. In this example, all entries in the zip archive dating from before December 31st, 2007, are removed from the archive. This is actually much easier if you use the RemoveSelectedEntries method. But I needed an example for RemoveEntry, so here it is.


             String ZipFileToRead = "ArchiveToModify.zip";
             System.DateTime Threshold = new System.DateTime(2007,12,31);
             using (ZipFile zip = ZipFile.Read(ZipFileToRead))
             {
               var EntriesToRemove = new System.Collections.Generic.List<ZipEntry>();
               foreach (ZipEntry e in zip)
               {
                 if (e.LastModified < Threshold)
                 {
                   // We cannot remove the entry from the list, within the context of
                   // an enumeration of said list.
                   // So we add the doomed entry to a list to be removed later.
                   EntriesToRemove.Add(e);
                 }
               }
            
               // actually remove the doomed entries.
               foreach (ZipEntry zombie in EntriesToRemove)
                 zip.RemoveEntry(zombie);
            
               zip.Comment= String.Format("This zip archive was updated at {0}.",
                                          System.DateTime.Now.ToString("G"));
            
               // save with a different name
               zip.Save("Archive-Updated.zip");
             }


               Dim ZipFileToRead As String = "ArchiveToModify.zip"
               Dim Threshold As New DateTime(2007, 12, 31)
               Using zip As ZipFile = ZipFile.Read(ZipFileToRead)
                   Dim EntriesToRemove As New System.Collections.Generic.List(Of ZipEntry)
                   Dim e As ZipEntry
                   For Each e In zip
                       If (e.LastModified < Threshold) Then
                           ' We cannot remove the entry from the list, within the context of
                           ' an enumeration of said list.
                           ' So we add the doomed entry to a list to be removed later.
                           EntriesToRemove.Add(e)
                       End If
                   Next
            
                   ' actually remove the doomed entries.
                   Dim zombie As ZipEntry
                   For Each zombie In EntriesToRemove
                       zip.RemoveEntry(zombie)
                   Next
                   zip.Comment = String.Format("This zip archive was updated at {0}.", DateTime.Now.ToString("G"))
                   'save as a different name
                   zip.Save("Archive-Updated.zip")
               End Using

The ZipEntry to remove from the zip.

Removes the ZipEntry with the given filename from the zip archive.

After calling RemoveEntry, the application must call Save to make the changes permanent. Thrown if the ZipFile is not updatable. Thrown if a ZipEntry with the specified filename does not exist in the ZipFile. This example shows one way to remove an entry with a given filename from an existing zip archive.


             String zipFileToRead= "PackedDocuments.zip";
             string candidate = "DatedMaterial.xps";
             using (ZipFile zip = ZipFile.Read(zipFileToRead))
             {
               if (zip.EntryFilenames.Contains(candidate))
               {
                 zip.RemoveEntry(candidate);
                 zip.Comment= String.Format("The file '{0}' has been removed from this archive.",
                                            Candidate);
                 zip.Save();
               }
             }


               Dim zipFileToRead As String = "PackedDocuments.zip"
               Dim candidate As String = "DatedMaterial.xps"
               Using zip As ZipFile = ZipFile.Read(zipFileToRead)
                   If zip.EntryFilenames.Contains(candidate) Then
                       zip.RemoveEntry(candidate)
                       zip.Comment = String.Format("The file '{0}' has been removed from this archive.", Candidate)
                       zip.Save
                   End If
               End Using

The name of the file, including any directory path, to remove from the zip. The filename match is not case-sensitive by default; you can use the CaseSensitiveRetrieval property to change this behavior. The pathname can use forward-slashes or backward slashes.

Closes the read and write streams associated to the ZipFile, if necessary.

The Dispose() method is generally employed implicitly, via a using(..) {..} statement. (Using...End Using in VB) If you do not employ a using statement, insure that your application calls Dispose() explicitly. For example, in a Powershell application, or an application that uses the COM interop interface, you must call Dispose() explicitly. This example extracts an entry selected by name, from the Zip file to the Console.


             using (ZipFile zip = ZipFile.Read(zipfile))
             {
               foreach (ZipEntry e in zip)
               {
                 if (WantThisEntry(e.FileName))
                   zip.Extract(e.FileName, Console.OpenStandardOutput());
               }
             } // Dispose() is called implicitly here.


             Using zip As ZipFile = ZipFile.Read(zipfile)
                 Dim e As ZipEntry
                 For Each e In zip
                   If WantThisEntry(e.FileName) Then
                       zip.Extract(e.FileName, Console.OpenStandardOutput())
                   End If
                 Next
             End Using ' Dispose is implicity called here

Disposes any managed resources, if the flag is set, then marks the instance disposed. This method is typically not called explicitly from application code.

Applications should call the no-arg Dispose method. indicates whether the method should dispose streams or not.

Default size of the buffer used for IO.

Checks a zip file to see if its directory is consistent.

In cases of data error, the directory within a zip file can get out of synch with the entries in the zip file. This method checks the given zip file and returns true if this has occurred. This method may take a long time to run for large zip files. This method is not supported in the Reduced or Compact Framework versions of DotNetZip. Developers using COM can use the ComHelper.CheckZip(String) method. The filename to of the zip file to check. true if the named zip file checks OK. Otherwise, false.

Checks a zip file to see if its directory is consistent, and optionally fixes the directory if necessary.

In cases of data error, the directory within a zip file can get out of synch with the entries in the zip file. This method checks the given zip file, and returns true if this has occurred. It also optionally fixes the zipfile, saving the fixed copy in Name_Fixed.zip. This method may take a long time to run for large zip files. It will take even longer if the file actually needs to be fixed, and if fixIfNecessary is true. This method is not supported in the Reduced or Compact Framework versions of DotNetZip. The filename to of the zip file to check. If true, the method will fix the zip file if necessary. a collection of messages generated while checking, indicating any problems that are found. true if the named zip is OK; false if the file needs to be fixed.

Rewrite the directory within a zipfile.

In cases of data error, the directory in a zip file can get out of synch with the entries in the zip file. This method attempts to fix the zip file if this has occurred. This can take a long time for large zip files. This won't work if the zip file uses a non-standard code page - neither IBM437 nor UTF-8. This method is not supported in the Reduced or Compact Framework versions of DotNetZip. Developers using COM can use the ComHelper.FixZipDirectory(String) method. The filename to of the zip file to fix.

Generic IEnumerator support, for use of a ZipFile in an enumeration.

You probably do not want to call GetEnumerator explicitly. Instead it is implicitly called when you use a loop in C#, or a For Each loop in VB.NET. This example reads a zipfile of a given name, then enumerates the entries in that zip file, and displays the information about each entry on the Console.


             using (ZipFile zip = ZipFile.Read(zipfile))
             {
               bool header = true;
               foreach (ZipEntry e in zip)
               {
                 if (header)
                 {
                    System.Console.WriteLine("Zipfile: {0}", zip.Name);
                    System.Console.WriteLine("Version Needed: 0x{0:X2}", e.VersionNeeded);
                    System.Console.WriteLine("BitField: 0x{0:X2}", e.BitField);
                    System.Console.WriteLine("Compression Method: 0x{0:X2}", e.CompressionMethod);
                    System.Console.WriteLine("\n{1,-22} {2,-6} {3,4}   {4,-8}  {0}",
                                 "Filename", "Modified", "Size", "Ratio", "Packed");
                    System.Console.WriteLine(new System.String('-', 72));
                    header = false;
                 }
            
                 System.Console.WriteLine("{1,-22} {2,-6} {3,4:F0}%   {4,-8}  {0}",
                             e.FileName,
                             e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
                             e.UncompressedSize,
                             e.CompressionRatio,
                             e.CompressedSize);
            
                 e.Extract();
               }
             }


               Dim ZipFileToExtract As String = "c:\foo.zip"
               Using zip As ZipFile = ZipFile.Read(ZipFileToExtract)
                   Dim header As Boolean = True
                   Dim e As ZipEntry
                   For Each e In zip
                       If header Then
                           Console.WriteLine("Zipfile: {0}", zip.Name)
                           Console.WriteLine("Version Needed: 0x{0:X2}", e.VersionNeeded)
                           Console.WriteLine("BitField: 0x{0:X2}", e.BitField)
                           Console.WriteLine("Compression Method: 0x{0:X2}", e.CompressionMethod)
                           Console.WriteLine(ChrW(10) & "{1,-22} {2,-6} {3,4}   {4,-8}  {0}", _
                             "Filename", "Modified", "Size", "Ratio", "Packed" )
                           Console.WriteLine(New String("-"c, 72))
                           header = False
                       End If
                       Console.WriteLine("{1,-22} {2,-6} {3,4:F0}%   {4,-8}  {0}", _
                         e.FileName, _
                         e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"), _
                         e.UncompressedSize, _
                         e.CompressionRatio, _
                         e.CompressedSize )
                       e.Extract
                   Next
               End Using

A generic enumerator suitable for use within a foreach loop.

An IEnumerator, for use of a ZipFile in a foreach construct.

This method is included for COM support. An application generally does not call this method directly. It is called implicitly by COM clients when enumerating the entries in the ZipFile instance. In VBScript, this is done with a For Each statement. In Javascript, this is done with new Enumerator(zipfile). The IEnumerator over the entries in the ZipFile.

Saves the ZipFile instance to a self-extracting zip archive.

The generated exe image will execute on any machine that has the .NET Framework 2.0 installed on it. The generated exe image is also a valid ZIP file, readable with DotNetZip or another Zip library or tool such as WinZip. There are two "flavors" of self-extracting archive. The WinFormsApplication version will pop up a GUI and allow the user to select a target directory into which to extract. There's also a checkbox allowing the user to specify to overwrite existing files, and another checkbox to allow the user to request that Explorer be opened to see the extracted files after extraction. The other flavor is ConsoleApplication. A self-extractor generated with that flavor setting will run from the command line. It accepts command-line options to set the overwrite behavior, and to specify the target extraction directory. There are a few temporary files created during the saving to a self-extracting zip. These files are created in the directory pointed to by , which defaults to . These temporary files are removed upon successful completion of this method. When a user runs the WinForms SFX, the user's personal directory () will be used as the default extract location. The user who runs the SFX will have the opportunity to change the extract directory before extracting. When the user runs the Command-Line SFX, the user must explicitly specify the directory to which to extract. The .NET Framework 2.0 is required on the computer when the self-extracting archive is run. NB: This method is not available in the version of DotNetZip build for the .NET Compact Framework, nor in the "Reduced" DotNetZip library.


             string DirectoryPath = "c:\\Documents\\Project7";
             using (ZipFile zip = new ZipFile())
             {
                 zip.AddDirectory(DirectoryPath, System.IO.Path.GetFileName(DirectoryPath));
                 zip.Comment = "This will be embedded into a self-extracting console-based exe";
                 zip.SaveSelfExtractor("archive.exe", SelfExtractorFlavor.ConsoleApplication);
             }


             Dim DirectoryPath As String = "c:\Documents\Project7"
             Using zip As New ZipFile()
                 zip.AddDirectory(DirectoryPath, System.IO.Path.GetFileName(DirectoryPath))
                 zip.Comment = "This will be embedded into a self-extracting console-based exe"
                 zip.SaveSelfExtractor("archive.exe", SelfExtractorFlavor.ConsoleApplication)
             End Using

a pathname, possibly fully qualified, to be created. Typically it will end in an .exe extension. Indicates whether a Winforms or Console self-extractor is desired.

Saves the ZipFile instance to a self-extracting zip archive, using the specified save options.

This method saves a self extracting archive, using the specified save options. These options include the flavor of the SFX, the default extract directory, the icon file, and so on. See the documentation for for more details. The user who runs the SFX will have the opportunity to change the extract directory before extracting. If at the time of extraction, the specified directory does not exist, the SFX will create the directory before extracting the files. This example saves a self-extracting archive that will use c:\ExtractHere as the default extract location.


             string DirectoryPath = "c:\\Documents\\Project7";
             using (ZipFile zip = new ZipFile())
             {
                 zip.AddDirectory(DirectoryPath, System.IO.Path.GetFileName(DirectoryPath));
                 zip.Comment = "This will be embedded into a self-extracting console-based exe";
                 SelfExtractorOptions options = new SelfExtractorOptions();
                 options.Flavor = SelfExtractorFlavor.ConsoleApplication;
                 options.DefaultExtractDirectory = "%USERPROFILE%\\ExtractHere";
                 options.PostExtractCommandLine = ExeToRunAfterExtract;
                 options.RemoveUnpackedFilesAfterExecute = true;
                 zip.SaveSelfExtractor("archive.exe", options);
             }


             Dim DirectoryPath As String = "c:\Documents\Project7"
             Using zip As New ZipFile()
                 zip.AddDirectory(DirectoryPath, System.IO.Path.GetFileName(DirectoryPath))
                 zip.Comment = "This will be embedded into a self-extracting console-based exe"
                 Dim options As New SelfExtractorOptions()
                 options.Flavor = SelfExtractorFlavor.ConsoleApplication
                 options.DefaultExtractDirectory = "%USERPROFILE%\\ExtractHere"
                 options.PostExtractCommandLine = ExeToRunAfterExtract
                 options.RemoveUnpackedFilesAfterExecute = True
                 zip.SaveSelfExtractor("archive.exe", options)
             End Using

The name of the EXE to generate. provides the options for how to save the Self-extracting archive.

Saves the Zip archive to a file, specified by the Name property of the ZipFile.

The ZipFile instance is written to storage, typically a zip file in a filesystem, only when the caller calls Save. The Save operation writes the zip content to a temporary file, and then renames the temporary file to the desired name. If necessary, this method will delete a pre-existing file before the rename. The property is specified either explicitly, or implicitly using one of the parameterized ZipFile constructors. For COM Automation clients, the Name property must be set explicitly, because COM Automation clients cannot call parameterized constructors. When using a filesystem file for the Zip output, it is possible to call Save multiple times on the ZipFile instance. With each call the zip content is re-written to the same output file. Data for entries that have been added to the ZipFile instance is written to the output when the Save method is called. This means that the input streams for those entries must be available at the time the application calls Save. If, for example, the application adds entries with AddEntry using a dynamically-allocated MemoryStream, the memory stream must not have been disposed before the call to Save. See the property for more discussion of the availability requirements of the input stream for an entry, and an approach for providing just-in-time stream lifecycle management. Thrown if you haven't specified a location or stream for saving the zip, either in the constructor or by setting the Name property, or if you try to save a regular zip archive to a filename with a .exe extension.

Save the file to a new zipfile, with the given name.

This method allows the application to explicitly specify the name of the zip file when saving. Use this when creating a new zip file, or when updating a zip archive. An application can also save a zip archive in several places by calling this method multiple times in succession, with different filenames. The ZipFile instance is written to storage, typically a zip file in a filesystem, only when the caller calls Save. The Save operation writes the zip content to a temporary file, and then renames the temporary file to the desired name. If necessary, this method will delete a pre-existing file before the rename. Thrown if you specify a directory for the filename. The name of the zip archive to save to. Existing files will be overwritten with great prejudice. This example shows how to create and Save a zip file.


             using (ZipFile zip = new ZipFile())
             {
               zip.AddDirectory(@"c:\reports\January");
               zip.Save("January.zip");
             }


             Using zip As New ZipFile()
               zip.AddDirectory("c:\reports\January")
               zip.Save("January.zip")
             End Using

This example shows how to update a zip file.


             using (ZipFile zip = ZipFile.Read("ExistingArchive.zip"))
             {
               zip.AddFile("NewData.csv");
               zip.Save("UpdatedArchive.zip");
             }


             Using zip As ZipFile = ZipFile.Read("ExistingArchive.zip")
               zip.AddFile("NewData.csv")
               zip.Save("UpdatedArchive.zip")
             End Using

Save the zip archive to the specified stream.

The ZipFile instance is written to storage - typically a zip file in a filesystem, but using this overload, the storage can be anything accessible via a writable stream - only when the caller calls Save. Use this method to save the zip content to a stream directly. A common scenario is an ASP.NET application that dynamically generates a zip file and allows the browser to download it. The application can call Save(Response.OutputStream) to write a zipfile directly to the output stream, without creating a zip file on the disk on the ASP.NET server. Be careful when saving a file to a non-seekable stream, including Response.OutputStream. When DotNetZip writes to a non-seekable stream, the zip archive is formatted in such a way that may not be compatible with all zip tools on all platforms. It's a perfectly legal and compliant zip file, but some people have reported problems opening files produced this way using the Mac OS archive utility. This example saves the zipfile content into a MemoryStream, and then gets the array of bytes from that MemoryStream.


             using (var zip = new Ionic.Zip.ZipFile())
             {
                 zip.CompressionLevel= Ionic.Zlib.CompressionLevel.BestCompression;
                 zip.Password = "VerySecret.";
                 zip.Encryption = EncryptionAlgorithm.WinZipAes128;
                 zip.AddFile(sourceFileName);
                 MemoryStream output = new MemoryStream();
                 zip.Save(output);
            
                 byte[] zipbytes = output.ToArray();
             }

The System.IO.Stream to write to. It must be writable.

Adds an item, either a file or a directory, to a zip file archive.

This method is handy if you are adding things to zip archive and don't want to bother distinguishing between directories or files. Any files are added as single entries. A directory added through this method is added recursively: all files and subdirectories contained within the directory are added to the ZipFile. The name of the item may be a relative path or a fully-qualified path. Remember, the items contained in ZipFile instance get written to the disk only when you call or a similar save method. The directory name used for the file within the archive is the same as the directory name (potentially a relative path) specified in the . For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. This method has two overloads. the name of the file or directory to add. The ZipEntry added.

Adds an item, either a file or a directory, to a zip file archive, explicitly specifying the directory path to be used in the archive.

If adding a directory, the add is recursive on all files and subdirectories contained within it. The name of the item may be a relative path or a fully-qualified path. The item added by this call to the ZipFile is not read from the disk nor written to the zip file archive until the application calls Save() on the ZipFile. This version of the method allows the caller to explicitly specify the directory path to be used in the archive, which would override the "natural" path of the filesystem file. Encryption will be used on the file data if the Password has been set on the ZipFile object, prior to calling this method. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. Thrown if the file or directory passed in does not exist. the name of the file or directory to add. The name of the directory path to use within the zip archive. This path need not refer to an extant directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on the fileOrDirectoryName. Passing the empty string ("") will insert the item at the root path within the archive. This example shows how to zip up a set of files into a flat hierarchy, regardless of where in the filesystem the files originated. The resulting zip archive will contain a toplevel directory named "flat", which itself will contain files Readme.txt, MyProposal.docx, and Image1.jpg. A subdirectory under "flat" called SupportFiles will contain all the files in the "c:\SupportFiles" directory on disk.


             String[] itemnames= {
               "c:\\fixedContent\\Readme.txt",
               "MyProposal.docx",
               "c:\\SupportFiles",  // a directory
               "images\\Image1.jpg"
             };
            
             try
             {
               using (ZipFile zip = new ZipFile())
               {
                 for (int i = 1; i < itemnames.Length; i++)
                 {
                   // will add Files or Dirs, recurses and flattens subdirectories
                   zip.AddItem(itemnames[i],"flat");
                 }
                 zip.Save(ZipToCreate);
               }
             }
             catch (System.Exception ex1)
             {
               System.Console.Error.WriteLine("exception: {0}", ex1);
             }


               Dim itemnames As String() = _
                 New String() { "c:\fixedContent\Readme.txt", _
                                "MyProposal.docx", _
                                "SupportFiles", _
                                "images\Image1.jpg" }
               Try
                   Using zip As New ZipFile
                       Dim i As Integer
                       For i = 1 To itemnames.Length - 1
                           ' will add Files or Dirs, recursing and flattening subdirectories.
                           zip.AddItem(itemnames(i), "flat")
                       Next i
                       zip.Save(ZipToCreate)
                   End Using
               Catch ex1 As Exception
                   Console.Error.WriteLine("exception: {0}", ex1.ToString())
               End Try

The ZipEntry added.

Adds a File to a Zip file archive.

This call collects metadata for the named file in the filesystem, including the file attributes and the timestamp, and inserts that metadata into the resulting ZipEntry. Only when the application calls Save() on the ZipFile, does DotNetZip read the file from the filesystem and then write the content to the zip file archive. This method will throw an exception if an entry with the same name already exists in the ZipFile. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. In this example, three files are added to a Zip archive. The ReadMe.txt file will be placed in the root of the archive. The .png file will be placed in a folder within the zip called photos\personal. The pdf file will be included into a folder within the zip called Desktop.


                try
                {
                  using (ZipFile zip = new ZipFile())
                  {
                    zip.AddFile("c:\\photos\\personal\\7440-N49th.png");
                    zip.AddFile("c:\\Desktop\\2008-Regional-Sales-Report.pdf");
                    zip.AddFile("ReadMe.txt");
            
                    zip.Save("Package.zip");
                  }
                }
                catch (System.Exception ex1)
                {
                  System.Console.Error.WriteLine("exception: " + ex1);
                }


              Try
                   Using zip As ZipFile = New ZipFile
                       zip.AddFile("c:\photos\personal\7440-N49th.png")
                       zip.AddFile("c:\Desktop\2008-Regional-Sales-Report.pdf")
                       zip.AddFile("ReadMe.txt")
                       zip.Save("Package.zip")
                   End Using
               Catch ex1 As Exception
                   Console.Error.WriteLine("exception: {0}", ex1.ToString)
               End Try

This method has two overloads. The name of the file to add. It should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. The ZipEntry corresponding to the File added.

Adds a File to a Zip file archive, potentially overriding the path to be used within the zip archive.

The file added by this call to the ZipFile is not written to the zip file archive until the application calls Save() on the ZipFile. This method will throw an exception if an entry with the same name already exists in the ZipFile. This version of the method allows the caller to explicitly specify the directory path to be used in the archive. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. In this example, three files are added to a Zip archive. The ReadMe.txt file will be placed in the root of the archive. The .png file will be placed in a folder within the zip called images. The pdf file will be included into a folder within the zip called files\docs, and will be encrypted with the given password.


             try
             {
               using (ZipFile zip = new ZipFile())
               {
                 // the following entry will be inserted at the root in the archive.
                 zip.AddFile("c:\\datafiles\\ReadMe.txt", "");
                 // this image file will be inserted into the "images" directory in the archive.
                 zip.AddFile("c:\\photos\\personal\\7440-N49th.png", "images");
                 // the following will result in a password-protected file called
                 // files\\docs\\2008-Regional-Sales-Report.pdf  in the archive.
                 zip.Password = "EncryptMe!";
                 zip.AddFile("c:\\Desktop\\2008-Regional-Sales-Report.pdf", "files\\docs");
                 zip.Save("Archive.zip");
               }
             }
             catch (System.Exception ex1)
             {
               System.Console.Error.WriteLine("exception: {0}", ex1);
             }


               Try
                   Using zip As ZipFile = New ZipFile
                       ' the following entry will be inserted at the root in the archive.
                       zip.AddFile("c:\datafiles\ReadMe.txt", "")
                       ' this image file will be inserted into the "images" directory in the archive.
                       zip.AddFile("c:\photos\personal\7440-N49th.png", "images")
                       ' the following will result in a password-protected file called
                       ' files\\docs\\2008-Regional-Sales-Report.pdf  in the archive.
                       zip.Password = "EncryptMe!"
                       zip.AddFile("c:\Desktop\2008-Regional-Sales-Report.pdf", "files\documents")
                       zip.Save("Archive.zip")
                   End Using
               Catch ex1 As Exception
                   Console.Error.WriteLine("exception: {0}", ex1)
               End Try

The name of the file to add. The name of the file may be a relative path or a fully-qualified path. Specifies a directory path to use to override any path in the fileName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on the fileName, if any. Passing the empty string ("") will insert the item at the root path within the archive. The ZipEntry corresponding to the file added.

This method removes a collection of entries from the ZipFile.

A collection of ZipEntry instances from this zip file to be removed. For example, you can pass in an array of ZipEntry instances; or you can call SelectEntries(), and then add or remove entries from that ICollection<ZipEntry> (ICollection(Of ZipEntry) in VB), and pass that ICollection to this method.

This method removes a collection of entries from the ZipFile, by name.

A collection of strings that refer to names of entries to be removed from the ZipFile. For example, you can pass in an array or a List of Strings that provide the names of entries to be removed.

This method adds a set of files to the ZipFile.

Use this method to add a set of files to the zip archive, in one call. For example, a list of files received from System.IO.Directory.GetFiles() can be added to a zip archive in one call. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. The collection of names of the files to add. Each string should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. This example shows how to create a zip file, and add a few files into it.


             String ZipFileToCreate = "archive1.zip";
             String DirectoryToZip = "c:\\reports";
             using (ZipFile zip = new ZipFile())
             {
               // Store all files found in the top level directory, into the zip archive.
               String[] filenames = System.IO.Directory.GetFiles(DirectoryToZip);
               zip.AddFiles(filenames);
               zip.Save(ZipFileToCreate);
             }


             Dim ZipFileToCreate As String = "archive1.zip"
             Dim DirectoryToZip As String = "c:\reports"
             Using zip As ZipFile = New ZipFile
                 ' Store all files found in the top level directory, into the zip archive.
                 Dim filenames As String() = System.IO.Directory.GetFiles(DirectoryToZip)
                 zip.AddFiles(filenames)
                 zip.Save(ZipFileToCreate)
             End Using

Adds or updates a set of files in the ZipFile.

Adds a set of files to the ZipFile, using the specified directory path in the archive.

Any directory structure that may be present in the filenames contained in the list is "flattened" in the archive. Each file in the list is added to the archive in the specified top-level directory. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. The names of the files to add. Each string should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. Specifies a directory path to use to override any path in the file name. Th is path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on each of the fileNames, if any. Passing the empty string ("") will insert the item at the root path within the archive.

Adds a set of files to the ZipFile, using the specified directory path in the archive, and preserving the full directory structure in the filenames.

If preserveDirHierarchy is true, any directory structure present in the filenames contained in the list is preserved in the archive. On the other hand, if preserveDirHierarchy is false, any directory structure that may be present in the filenames contained in the list is "flattened" in the archive; Each file in the list is added to the archive in the specified top-level directory. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. The names of the files to add. Each string should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. Specifies a directory path to use to override any path in the file name. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on each of the fileNames, if any. Passing the empty string ("") will insert the item at the root path within the archive. whether the entries in the zip archive will reflect the directory hierarchy that is present in the various filenames. For example, if includes two paths, \Animalia\Chordata\Mammalia\Info.txt and \Plantae\Magnoliophyta\Dicotyledon\Info.txt, then calling this method with = false will result in an exception because of a duplicate entry name, while calling this method with = true will result in the full direcory paths being included in the entries added to the ZipFile.

Adds or updates a set of files to the ZipFile, using the specified directory path in the archive.

Any files that already exist in the archive are updated. Any files that don't yet exist in the archive are added. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. The names of the files to add or update. Each string should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. Specifies a directory path to use to override any path in the file name. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on each of the fileNames, if any. Passing the empty string ("") will insert the item at the root path within the archive.

Adds or Updates a File in a Zip file archive.

This method adds a file to a zip archive, or, if the file already exists in the zip archive, this method Updates the content of that given filename in the zip archive. The UpdateFile method might more accurately be called "AddOrUpdateFile". Upon success, there is no way for the application to learn whether the file was added versus updated. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. This example shows how to Update an existing entry in a zipfile. The first call to UpdateFile adds the file to the newly-created zip archive. The second call to UpdateFile updates the content for that file in the zip archive.


             using (ZipFile zip1 = new ZipFile())
             {
               // UpdateFile might more accurately be called "AddOrUpdateFile"
               zip1.UpdateFile("MyDocuments\\Readme.txt");
               zip1.UpdateFile("CustomerList.csv");
               zip1.Comment = "This zip archive has been created.";
               zip1.Save("Content.zip");
             }
            
             using (ZipFile zip2 = ZipFile.Read("Content.zip"))
             {
               zip2.UpdateFile("Updates\\Readme.txt");
               zip2.Comment = "This zip archive has been updated: The Readme.txt file has been changed.";
               zip2.Save();
             }


               Using zip1 As New ZipFile
                   ' UpdateFile might more accurately be called "AddOrUpdateFile"
                   zip1.UpdateFile("MyDocuments\Readme.txt")
                   zip1.UpdateFile("CustomerList.csv")
                   zip1.Comment = "This zip archive has been created."
                   zip1.Save("Content.zip")
               End Using
            
               Using zip2 As ZipFile = ZipFile.Read("Content.zip")
                   zip2.UpdateFile("Updates\Readme.txt")
                   zip2.Comment = "This zip archive has been updated: The Readme.txt file has been changed."
                   zip2.Save
               End Using

The name of the file to add or update. It should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. The ZipEntry corresponding to the File that was added or updated.

Adds or Updates a File in a Zip file archive.

This method adds a file to a zip archive, or, if the file already exists in the zip archive, this method Updates the content of that given filename in the zip archive. This version of the method allows the caller to explicitly specify the directory path to be used in the archive. The entry to be added or updated is found by using the specified directory path, combined with the basename of the specified filename. Upon success, there is no way for the application to learn if the file was added versus updated. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. The name of the file to add or update. It should refer to a file in the filesystem. The name of the file may be a relative path or a fully-qualified path. Specifies a directory path to use to override any path in the fileName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on the fileName, if any. Passing the empty string ("") will insert the item at the root path within the archive. The ZipEntry corresponding to the File that was added or updated.

Add or update a directory in a zip archive.

Add or update a directory in the zip archive at the specified root directory in the archive.

If the specified directory does not exist in the archive, then this method is equivalent to calling AddDirectory(). If the specified directory already exists in the archive, then this method updates any existing entries, and adds any new entries. Any entries that are in the zip archive but not in the specified directory, are left alone. In other words, the contents of the zip file will be a union of the previous contents and the new files. The path to the directory to be added to the zip archive, or updated in the zip archive. Specifies a directory path to use to override any path in the directoryName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on the directoryName, if any. Passing the empty string ("") will insert the item at the root path within the archive. The ZipEntry corresponding to the Directory that was added or updated.

Add or update a file or directory in the zip archive.

This is useful when the application is not sure or does not care if the item to be added is a file or directory, and does not know or does not care if the item already exists in the ZipFile. Calling this method is equivalent to calling RemoveEntry() if an entry by the same name already exists, followed calling by AddItem(). For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. the path to the file or directory to be added or updated.

Add or update a file or directory.

This method is useful when the application is not sure or does not care if the item to be added is a file or directory, and does not know or does not care if the item already exists in the ZipFile. Calling this method is equivalent to calling RemoveEntry(), if an entry by that name exists, and then calling AddItem(). This version of the method allows the caller to explicitly specify the directory path to be used for the item being added to the archive. The entry or entries that are added or updated will use the specified DirectoryPathInArchive. Extracting the entry from the archive will result in a file stored in that directory path. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. The path for the File or Directory to be added or updated. Specifies a directory path to use to override any path in the itemName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (Nothing in VB) will use the path on the itemName, if any. Passing the empty string ("") will insert the item at the root path within the archive.

Adds a named entry into the zip archive, taking content for the entry from a string.


             string Content = "This string will be the content of the Readme.txt file in the zip archive.";
             using (ZipFile zip1 = new ZipFile())
             {
               zip1.AddFile("MyDocuments\\Resume.doc", "files");
               zip1.AddEntry("Readme.txt", Content);
               zip1.Comment = "This zip file was created at " + System.DateTime.Now.ToString("G");
               zip1.Save("Content.zip");
             }


             Public Sub Run()
               Dim Content As String = "This string will be the content of the Readme.txt file in the zip archive."
               Using zip1 As ZipFile = New ZipFile
                 zip1.AddEntry("Readme.txt", Content)
                 zip1.AddFile("MyDocuments\Resume.doc", "files")
                 zip1.Comment = ("This zip file was created at " & DateTime.Now.ToString("G"))
                 zip1.Save("Content.zip")
               End Using
             End Sub

Adds a named entry into the zip archive, taking content for the entry from a string, and using the specified text encoding.

Calling this method creates an entry using the given fileName and directory path within the archive. There is no need for a file by the given name to exist in the filesystem; the name is used within the zip archive only. The content for the entry, a string value, is encoded using the given text encoding. No Byte-order-mark (BOM) is emitted into the file. If you wish to create within a zip file a file entry with Unicode-encoded content that includes a byte-order-mark, you can convert your string to a byte array using the appropriate System.Text.Encoding.GetBytes() method, then prepend to that byte array the output of System.Text.Encoding.GetPreamble(), and use the method, to add the entry. The name, including any path, to use within the archive for the entry. The content of the file, should it be extracted from the zip. The text encoding to use when encoding the string. Be aware: This is distinct from the text encoding used to encode the fileName, as specified in . The ZipEntry added.

Create an entry in the ZipFile using the given Stream as input. The entry will have the given filename.

The application can provide an open, readable stream; in this case it will be read during the call to or one of its overloads. In cases where a large number of streams will be added to the ZipFile, the application may wish to avoid maintaining all of the streams open simultaneously. To handle this situation, the application should use the overload. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. This example adds a single entry to a ZipFile via a Stream.


             String zipToCreate = "Content.zip";
             String fileNameInArchive = "Content-From-Stream.bin";
             using (System.IO.Stream streamToRead = MyStreamOpener())
             {
               using (ZipFile zip = new ZipFile())
               {
                 ZipEntry entry= zip.AddEntry(fileNameInArchive, streamToRead);
                 zip.AddFile("Readme.txt");
                 zip.Save(zipToCreate);  // the stream is read implicitly here
               }
             }


             Dim zipToCreate As String = "Content.zip"
             Dim fileNameInArchive As String = "Content-From-Stream.bin"
             Using streamToRead as System.IO.Stream = MyStreamOpener()
               Using zip As ZipFile = New ZipFile()
                 Dim entry as ZipEntry = zip.AddEntry(fileNameInArchive, streamToRead)
                 zip.AddFile("Readme.txt")
                 zip.Save(zipToCreate)  '' the stream is read implicitly, here
               End Using
             End Using

The name, including any path, which is shown in the zip file for the added entry. The input stream from which to grab content for the file The ZipEntry added.

Add a ZipEntry for which content is written directly by the application.

When the application needs to write the zip entry data, use this method to add the ZipEntry. For example, in the case that the application wishes to write the XML representation of a DataSet into a ZipEntry, the application can use this method to do so. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. NB: With PKZip encryption, it's necessary to compute the CRC before compressing or encrypting the data. Therefore, when using PKZip encryption with a WriteDelegate, the WriteDelegate will be called twice: once to compute the CRC, and the second time to (potentially) compress and encrypt. For each call of the delegate, your application must stream the same entry data in its entirety. If your application writes different data during the second call, it will result in a corrupt zip file. the name of the entry to add the delegate which will write the entry content the ZipEntry added This example shows an application filling a DataSet, then saving the contents of that DataSet as XML, into a ZipEntry in a ZipFile, using an anonymous delegate in C#. The DataSet XML is never saved to a disk file.


             var c1= new System.Data.SqlClient.SqlConnection(connstring1);
             var da = new System.Data.SqlClient.SqlDataAdapter()
                 {
                     SelectCommand=  new System.Data.SqlClient.SqlCommand(strSelect, c1)
                 };
            
             DataSet ds1 = new DataSet();
             da.Fill(ds1, "Invoices");
            
             using(Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile())
             {
                 zip.AddEntry(zipEntryName, (name,stream) => ds1.WriteXml(stream) );
                 zip.Save(zipFileName);
             }

This example uses an anonymous method in C# as the WriteDelegate to provide the data for the ZipEntry. The example is a bit contrived - the AddFile() method is a simpler way to insert the contents of a file into an entry in a zip file. On the other hand, if there is some sort of processing or transformation of the file contents required before writing, the application could use the WriteDelegate to do it, in this way.


             using (var input = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite ))
             {
                 using(Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile())
                 {
                     zip.AddEntry(zipEntryName, (name,output) =>
                         {
                             byte[] buffer = new byte[BufferSize];
                             int n;
                             while ((n = input.Read(buffer, 0, buffer.Length)) != 0)
                             {
                                 // could transform the data here...
                                 output.Write(buffer, 0, n);
                                 // could update a progress bar here
                             }
                         });
            
                     zip.Save(zipFileName);
                 }
             }

This example uses a named delegate in VB to write data for the given ZipEntry (VB9 does not have anonymous delegates). The example here is a bit contrived - a simpler way to add the contents of a file to a ZipEntry is to simply use the appropriate AddFile() method. The key scenario for which the WriteDelegate makes sense is saving a DataSet, in XML format, to the zip file. The DataSet can write XML to a stream, and the WriteDelegate is the perfect place to write into the zip file. There may be other data structures that can write to a stream, but cannot be read as a stream. The WriteDelegate would be appropriate for those cases as well.


             Private Sub WriteEntry (ByVal name As String, ByVal output As Stream)
                 Using input As FileStream = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
                     Dim n As Integer = -1
                     Dim buffer As Byte() = New Byte(BufferSize){}
                     Do While n <> 0
                         n = input.Read(buffer, 0, buffer.Length)
                         output.Write(buffer, 0, n)
                     Loop
                 End Using
             End Sub
            
             Public Sub Run()
                 Using zip = New ZipFile
                     zip.AddEntry(zipEntryName, New WriteDelegate(AddressOf WriteEntry))
                     zip.Save(zipFileName)
                 End Using
             End Sub

Add an entry, for which the application will provide a stream, just-in-time.

In cases where the application wishes to open the stream that holds the content for the ZipEntry, on a just-in-time basis, the application can use this method and provide delegates to open and close the stream. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. This example uses anonymous methods in C# to open and close the source stream for the content for a zip entry. In a real application, the logic for the OpenDelegate would probably be more involved.


             using(Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile())
             {
                 zip.AddEntry(zipEntryName,
                              (name) =>  File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite ),
                              (name, stream) =>  stream.Close()
                              );
            
                 zip.Save(zipFileName);
             }

This example uses delegates in VB.NET to open and close the the source stream for the content for a zip entry. VB 9.0 lacks support for "Sub" lambda expressions, and so the CloseDelegate must be an actual, named Sub.


            
             Function MyStreamOpener(ByVal entryName As String) As Stream
                 '' This simply opens a file.  You probably want to do somethinig
                 '' more involved here: open a stream to read from a database,
                 '' open a stream on an HTTP connection, and so on.
                 Return File.OpenRead(entryName)
             End Function
            
             Sub MyStreamCloser(entryName As String, stream As Stream)
                 stream.Close()
             End Sub
            
             Public Sub Run()
                 Dim dirToZip As String = "fodder"
                 Dim zipFileToCreate As String = "Archive.zip"
                 Dim opener As OpenDelegate = AddressOf MyStreamOpener
                 Dim closer As CloseDelegate = AddressOf MyStreamCloser
                 Dim numFilestoAdd As Int32 = 4
                 Using zip As ZipFile = New ZipFile
                     Dim i As Integer
                     For i = 0 To numFilesToAdd - 1
                         zip.AddEntry(String.Format("content-{0:000}.txt"), opener, closer)
                     Next i
                     zip.Save(zipFileToCreate)
                 End Using
             End Sub

the name of the entry to add the delegate that will be invoked to open the stream the delegate that will be invoked to close the stream the ZipEntry added

Updates the given entry in the ZipFile, using the given string as input.

Calling this method is equivalent to removing the ZipEntry for the given file name and directory path, if it exists, and then calling . See the documentation for that method for further explanation. The name, including any path, to use within the archive for the entry. The content of the file, should it be extracted from the zip. The ZipEntry added.

Updates the given entry in the ZipFile, using the given string as content for the ZipEntry.

Updates the given entry in the ZipFile, using the given stream as input, and the given filename and given directory Path.

Calling the method is equivalent to calling RemoveEntry() if an entry by the same name already exists, and then calling AddEntry() with the given fileName and stream. The stream must be open and readable during the call to ZipFile.Save. You can dispense the stream on a just-in-time basis using the property. Check the documentation of that property for more information. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to the ZipEntry added. The name, including any path, to use within the archive for the entry. The input stream from which to read file data. The ZipEntry added.

Add an entry into the zip archive using the given filename and directory path within the archive, and the given content for the file. No file is created in the filesystem.

The data to use for the entry. The name, including any path, to use within the archive for the entry. The ZipEntry added.

Updates the given entry in the ZipFile, using the given byte array as content for the entry.

Adds the contents of a filesystem directory to a Zip file archive.

The name of the directory may be a relative path or a fully-qualified path. Any files within the named directory are added to the archive. Any subdirectories within the named directory are also added to the archive, recursively. Top-level entries in the named directory will appear as top-level entries in the zip archive. Entries in subdirectories in the named directory will result in entries in subdirectories in the zip archive. If you want the entries to appear in a containing directory in the zip archive itself, then you should call the AddDirectory() overload that allows you to explicitly specify a directory path for use in the archive. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. This method has 2 overloads. The name of the directory to add. The ZipEntry added.

Adds the contents of a filesystem directory to a Zip file archive, overriding the path to be used for entries in the archive.

The name of the directory may be a relative path or a fully-qualified path. The add operation is recursive, so that any files or subdirectories within the name directory are also added to the archive. Top-level entries in the named directory will appear as top-level entries in the zip archive. Entries in subdirectories in the named directory will result in entries in subdirectories in the zip archive. For ZipFile properties including , , , , , , and , their respective values at the time of this call will be applied to each ZipEntry added. In this code, calling the ZipUp() method with a value of "c:\reports" for the directory parameter will result in a zip file structure in which all entries are contained in a toplevel "reports" directory.


             public void ZipUp(string targetZip, string directory)
             {
               using (var zip = new ZipFile())
               {
                 zip.AddDirectory(directory, System.IO.Path.GetFileName(directory));
                 zip.Save(targetZip);
               }
             }

The name of the directory to add. Specifies a directory path to use to override any path in the DirectoryName. This path may, or may not, correspond to a real directory in the current filesystem. If the zip is later extracted, this is the path used for the extracted file or directory. Passing null (Nothing in VB) or the empty string ("") will insert the items at the root path within the archive. The ZipEntry added.

Creates a directory in the zip archive.

Use this when you want to create a directory in the archive but there is no corresponding filesystem representation for that directory. You will probably not need to do this in your code. One of the only times you will want to do this is if you want an empty directory in the zip archive. The reason: if you add a file to a zip archive that is stored within a multi-level directory, all of the directory tree is implicitly created in the zip archive. The name of the directory to create in the archive. The ZipEntry added.

Adds to the ZipFile a set of files from the disk that conform to the specified criteria.

This method selects files from the the current working directory matching the specified criteria, and adds them to the ZipFile. The selection does not recurse into subdirectories. Specify the criteria in statements of 3 elements: a noun, an operator, and a value. Consider the string "name != *.doc" . The noun is "name". The operator is "!=", implying "Not Equal". The value is "*.doc". That criterion, in English, says "all files with a name that does not end in the .doc extension." Supported nouns include "name" for the filename; "atime", "mtime", and "ctime" for last access time, last modfied time, and created time of the file, respectively; "attributes" for the file attributes; and "size" for the file length (uncompressed). The "attributes" and "name" nouns both support = and != as operators. The "size", "atime", "mtime", and "ctime" nouns support = and !=, and >, >=, <, <= as well. The times are taken to be expressed in "local time". Specify values for the file attributes as a string with one or more of the characters H,R,S,A in any order, implying Hidden, ReadOnly, System, and Archive, respectively. To specify a time, use YYYY-MM-DD-HH:mm:ss as the format. If you omit the HH:mm:ss portion, it is assumed to be 00:00:00 (midnight). The value for a size criterion is expressed in integer quantities of bytes, kilobytes (use k or kb after the number), megabytes (m or mb), or gigabytes (g or gb). The value for a name is a pattern to match against the filename, potentially including wildcards. The pattern follows CMD.exe glob rules: * implies one or more of any character (not including dot), while ? implies one character (not including dot). If the name pattern contains any slashes, it is matched to the entire filename, including the path; otherwise, it is matched against only the filename without the path. This means a pattern of "*\*.*" matches all files one directory level deep, while a pattern of "*.*" matches all files in all directories. To specify a name pattern that includes spaces, use single quotes around the pattern. A pattern of "'* *.*'" will match all files that have spaces in the filename. The full criteria string for that would be "name = '* *.*'" . Some examples: criteria Files retrieved name != *.xls any file with an extension that is not .xls name = *.mp3 any file with a .mp3 extension. *.mp3 (same as above) any file with a .mp3 extension. attributes = A all files whose attributes include the Archive bit. attributes != H all files whose attributes do not include the Hidden bit. mtime > 2009-01-01 all files with a last modified time after January 1st, 2009. size > 2gb all files whose uncompressed size is greater than 2gb. You can combine criteria with the conjunctions AND or OR. Using a string like "name = *.txt AND size >= 100k" for the selectionCriteria retrieves entries whose names end in .txt, and whose uncompressed size is greater than or equal to 100 kilobytes. For more complex combinations of criteria, you can use parenthesis to group clauses in the boolean logic. Without parenthesis, the precedence of the criterion atoms is determined by order of appearance. Unlike the C# language, the AND conjunction does not take precendence over the logical OR. This is important only in strings that contain 3 or more criterion atoms. In other words, "name = *.txt and size > 1000 or attributes = H" implies "((name = *.txt AND size > 1000) OR attributes = H)" while "attributes = H OR name = *.txt and size > 1000" evaluates to "((attributes = H OR name = *.txt) AND size > 1000)". When in doubt, use parenthesis. Using time properties requires some extra care. If you want to retrieve all entries that were last updated on 2009 February 14, specify a time range like so:"mtime >= 2009-02-14 AND mtime < 2009-02-15". Read this to say: all files updated after 12:00am on February 14th, until 12:00am on February 15th. You can use the same bracketing approach to specify any time period - a year, a month, a week, and so on. The syntax allows one special case: if you provide a string with no spaces, it is treated as a pattern to match for the filename. Therefore a string like "*.xls" will be equivalent to specifying "name = *.xls". There is no logic in this method that insures that the file inclusion criteria are internally consistent. For example, it's possible to specify criteria that says the file must have a size of less than 100 bytes, as well as a size that is greater than 1000 bytes. Obviously no file will ever satisfy such criteria, but this method does not detect such logical inconsistencies. The caller is responsible for insuring the criteria are sensible. This example zips up all *.csv files in the current working directory.


             using (ZipFile zip = new ZipFile())
             {
                 // To just match on filename wildcards,
                 // use the shorthand form of the selectionCriteria string.
                 zip.AddSelectedFiles("*.csv");
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile()
                 zip.AddSelectedFiles("*.csv")
                 zip.Save(PathToZipArchive)
             End Using

The criteria for file selection

Adds to the ZipFile a set of files from the disk that conform to the specified criteria.

This method selects files from the the current working directory matching the specified criteria, and adds them to the ZipFile. If recurseDirectories is true, files are also selected from subdirectories, and the directory structure in the filesystem is reproduced in the zip archive, rooted at the directory specified by directoryOnDisk. For details on the syntax for the selectionCriteria parameter, see . This example zips up all *.xml files in the current working directory, or any subdirectory, that are larger than 1mb.


             using (ZipFile zip = new ZipFile())
             {
                 // Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", true);
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile()
                 ' Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", true)
                 zip.Save(PathToZipArchive)
             End Using

The criteria for file selection If true, the file selection will recurse into subdirectories.

Adds to the ZipFile a set of files from the disk that conform to the specified criteria.

This method selects files from the the specified disk directory matching the specified criteria, and adds them to the ZipFile. The search does not recurse into subdirectores. For details on the syntax for the selectionCriteria parameter, see . This example zips up all *.xml files larger than 1mb in the directory given by "d:\rawdata".


             using (ZipFile zip = new ZipFile())
             {
                 // Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", "d:\\rawdata");
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile()
                 ' Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", "d:\rawdata)
                 zip.Save(PathToZipArchive)
             End Using

The criteria for file selection The name of the directory on the disk from which to select files.

Adds to the ZipFile a set of files from the disk that conform to the specified criteria.

This method selects files from the the specified disk directory matching the specified selection criteria, and adds them to the ZipFile. If recurseDirectories is true, files are also selected from subdirectories, and the directory structure in the filesystem is reproduced in the zip archive, rooted at the directory specified by directoryOnDisk. For details on the syntax for the selectionCriteria parameter, see . This example zips up all *.csv files in the "files" directory, or any subdirectory, that have been saved since 2009 February 14th.


             using (ZipFile zip = new ZipFile())
             {
                 // Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.csv  and  mtime > 2009-02-14", "files", true);
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile()
                 ' Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.csv  and  mtime > 2009-02-14", "files", true)
                 zip.Save(PathToZipArchive)
             End Using

The criteria for file selection The name of the directory on the disk from which to select files. If true, the file selection will recurse into subdirectories.

Adds to the ZipFile a selection of files from the disk that conform to the specified criteria.

This method selects files from the specified disk directory matching the specified selection criteria, and adds those files to the ZipFile, using the specified directory path in the archive. The search does not recurse into subdirectories. For details on the syntax for the selectionCriteria parameter, see . This example zips up all *.psd files in the "photos" directory that have been saved since 2009 February 14th, and puts them all in a zip file, using the directory name of "content" in the zip archive itself. When the zip archive is unzipped, the folder containing the .psd files will be named "content".


             using (ZipFile zip = new ZipFile())
             {
                 // Use a compound expression in the selectionCriteria string.
                 zip.AddSelectedFiles("name = *.psd  and  mtime > 2009-02-14", "photos", "content");
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile
                 zip.AddSelectedFiles("name = *.psd  and  mtime > 2009-02-14", "photos", "content")
                 zip.Save(PathToZipArchive)
             End Using

The criteria for selection of files to Add The name of the directory on the disk from which to select files. Specifies a directory path to use to override any path in the FileName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (nothing in VB) will use the path on the FileName, if any. Passing the empty string ("") will insert the item at the root path within the archive.

Adds to the ZipFile a selection of files from the disk that conform to the specified criteria.

This method selects files from the specified disk directory that match the specified selection criteria, and adds those files to the ZipFile, using the specified directory path in the archive. If recurseDirectories is true, files are also selected from subdirectories, and the directory structure in the filesystem is reproduced in the zip archive, rooted at the directory specified by directoryOnDisk. For details on the syntax for the selectionCriteria parameter, see . This example zips up all files that are NOT *.pst files, in the current working directory and any subdirectories.


             using (ZipFile zip = new ZipFile())
             {
                 zip.AddSelectedFiles("name != *.pst", SourceDirectory, "backup", true);
                 zip.Save(PathToZipArchive);
             }


             Using zip As ZipFile = New ZipFile
                 zip.AddSelectedFiles("name != *.pst", SourceDirectory, "backup", true)
                 zip.Save(PathToZipArchive)
             End Using

Updates the ZipFile with a selection of files from the disk that conform to the specified criteria.

This method selects files from the specified disk directory that match the specified selection criteria, and Updates the ZipFile with those files, using the specified directory path in the archive. If recurseDirectories is true, files are also selected from subdirectories, and the directory structure in the filesystem is reproduced in the zip archive, rooted at the directory specified by directoryOnDisk. For details on the syntax for the selectionCriteria parameter, see . The criteria for selection of files to Add The name of the directory on the disk from which to select files. Specifies a directory path to use to override any path in the FileName. This path may, or may not, correspond to a real directory in the current filesystem. If the files within the zip are later extracted, this is the path used for the extracted file. Passing null (nothing in VB) will use the path on the FileName, if any. Passing the empty string ("") will insert the item at the root path within the archive. If true, the method also scans subdirectories for files matching the criteria.

Retrieve entries from the zipfile by specified criteria.

This method allows callers to retrieve the collection of entries from the zipfile that fit the specified criteria. The criteria are described in a string format, and can include patterns for the filename; constraints on the size of the entry; constraints on the last modified, created, or last accessed time for the file described by the entry; or the attributes of the entry. For details on the syntax for the selectionCriteria parameter, see . This method is intended for use with a ZipFile that has been read from storage. When creating a new ZipFile, this method will work only after the ZipArchive has been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip archive from storage.) Calling SelectEntries on a ZipFile that has not yet been saved will deliver undefined results. Thrown if selectionCriteria has an invalid syntax. This example selects all the PhotoShop files from within an archive, and extracts them to the current working directory.


             using (ZipFile zip1 = ZipFile.Read(ZipFileName))
             {
                 var PhotoShopFiles = zip1.SelectEntries("*.psd");
                 foreach (ZipEntry psd in PhotoShopFiles)
                 {
                     psd.Extract();
                 }
             }


             Using zip1 As ZipFile = ZipFile.Read(ZipFileName)
                 Dim PhotoShopFiles as ICollection(Of ZipEntry)
                 PhotoShopFiles = zip1.SelectEntries("*.psd")
                 Dim psd As ZipEntry
                 For Each psd In PhotoShopFiles
                     psd.Extract
                 Next
             End Using

the string that specifies which entries to select a collection of ZipEntry objects that conform to the inclusion spec

Retrieve entries from the zipfile by specified criteria.


             using (ZipFile zip1 = ZipFile.Read(ZipFileName))
             {
                 var UpdatedPhotoShopFiles = zip1.SelectEntries("*.psd", "UpdatedFiles");
                 foreach (ZipEntry e in UpdatedPhotoShopFiles)
                 {
                     // prompt for extract here
                     if (WantExtract(e.FileName))
                         e.Extract();
                 }
             }


             Using zip1 As ZipFile = ZipFile.Read(ZipFileName)
                 Dim UpdatedPhotoShopFiles As ICollection(Of ZipEntry) = zip1.SelectEntries("*.psd", "UpdatedFiles")
                 Dim e As ZipEntry
                 For Each e In UpdatedPhotoShopFiles
                     ' prompt for extract here
                     If Me.WantExtract(e.FileName) Then
                         e.Extract
                     End If
                 Next
             End Using

the string that specifies which entries to select the directory in the archive from which to select entries. If null, then all directories in the archive are used. a collection of ZipEntry objects that conform to the inclusion spec

Remove entries from the zipfile by specified criteria.

This method allows callers to remove the collection of entries from the zipfile that fit the specified criteria. The criteria are described in a string format, and can include patterns for the filename; constraints on the size of the entry; constraints on the last modified, created, or last accessed time for the file described by the entry; or the attributes of the entry. For details on the syntax for the selectionCriteria parameter, see . This method is intended for use with a ZipFile that has been read from storage. When creating a new ZipFile, this method will work only after the ZipArchive has been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip archive from storage.) Calling SelectEntries on a ZipFile that has not yet been saved will deliver undefined results. Thrown if selectionCriteria has an invalid syntax. This example removes all entries in a zip file that were modified prior to January 1st, 2008.


             using (ZipFile zip1 = ZipFile.Read(ZipFileName))
             {
                 // remove all entries from prior to Jan 1, 2008
                 zip1.RemoveEntries("mtime < 2008-01-01");
                 // don't forget to save the archive!
                 zip1.Save();
             }


             Using zip As ZipFile = ZipFile.Read(ZipFileName)
                 ' remove all entries from prior to Jan 1, 2008
                 zip1.RemoveEntries("mtime < 2008-01-01")
                 ' do not forget to save the archive!
                 zip1.Save
             End Using

the string that specifies which entries to select the number of entries removed

Remove entries from the zipfile by specified criteria, and within the specified path in the archive.


             using (ZipFile zip1 = ZipFile.Read(ZipFileName))
             {
                 // remove all entries from prior to Jan 1, 2008
                 zip1.RemoveEntries("mtime < 2008-01-01", "documents");
                 // a call to ZipFile.Save will make the modifications permanent
                 zip1.Save();
             }


             Using zip As ZipFile = ZipFile.Read(ZipFileName)
                 ' remove all entries from prior to Jan 1, 2008
                 zip1.RemoveEntries("mtime < 2008-01-01", "documents")
                 ' a call to ZipFile.Save will make the modifications permanent
                 zip1.Save
             End Using

the string that specifies which entries to select the directory in the archive from which to select entries. If null, then all directories in the archive are used. the number of entries removed

Selects and Extracts a set of Entries from the ZipFile.

The entries are extracted into the current working directory. If any of the files to be extracted already exist, then the action taken is as specified in the property on the corresponding ZipEntry instance. By default, the action taken in this case is to throw an exception. For information on the syntax of the selectionCriteria string, see . This example shows how extract all XML files modified after 15 January 2009.


             using (ZipFile zip = ZipFile.Read(zipArchiveName))
             {
               zip.ExtractSelectedEntries("name = *.xml  and  mtime > 2009-01-15");
             }

the selection criteria for entries to extract.

Selects and Extracts a set of Entries from the ZipFile.

The entries are extracted into the current working directory. When extraction would would overwrite an existing filesystem file, the action taken is as specified in the parameter. For information on the syntax of the string describing the entry selection criteria, see . This example shows how extract all XML files modified after 15 January 2009, overwriting any existing files.


             using (ZipFile zip = ZipFile.Read(zipArchiveName))
             {
               zip.ExtractSelectedEntries("name = *.xml  and  mtime > 2009-01-15",
                                          ExtractExistingFileAction.OverwriteSilently);
             }

the selection criteria for entries to extract. The action to take if extraction would overwrite an existing file.

Selects and Extracts a set of Entries from the ZipFile.

The entries are selected from the specified directory within the archive, and then extracted into the current working directory. If any of the files to be extracted already exist, then the action taken is as specified in the property on the corresponding ZipEntry instance. By default, the action taken in this case is to throw an exception. For information on the syntax of the string describing the entry selection criteria, see . This example shows how extract all XML files modified after 15 January 2009, and writes them to the "unpack" directory.


             using (ZipFile zip = ZipFile.Read(zipArchiveName))
             {
               zip.ExtractSelectedEntries("name = *.xml  and  mtime > 2009-01-15","unpack");
             }

the selection criteria for entries to extract. the directory in the archive from which to select entries. If null, then all directories in the archive are used.

Selects and Extracts a set of Entries from the ZipFile.

The entries are extracted into the specified directory. If any of the files to be extracted already exist, an exception will be thrown. For information on the syntax of the string describing the entry selection criteria, see . the selection criteria for entries to extract. the directory in the archive from which to select entries. If null, then all directories in the archive are used. the directory on the disk into which to extract. It will be created if it does not exist.

Selects and Extracts a set of Entries from the ZipFile.

The entries are extracted into the specified directory. When extraction would would overwrite an existing filesystem file, the action taken is as specified in the parameter. For information on the syntax of the string describing the entry selection criteria, see . This example shows how extract all files with an XML extension or with a size larger than 100,000 bytes, and puts them in the unpack directory. For any files that already exist in that destination directory, they will not be overwritten.


             using (ZipFile zip = ZipFile.Read(zipArchiveName))
             {
               zip.ExtractSelectedEntries("name = *.xml  or  size > 100000",
                                          null,
                                          "unpack",
                                          ExtractExistingFileAction.DontOverwrite);
             }

the selection criteria for entries to extract. The directory on the disk into which to extract. It will be created if it does not exist. The directory in the archive from which to select entries. If null, then all directories in the archive are used. The action to take if extraction would overwrite an existing file.

Extracts all of the items in the zip archive, to the specified path in the filesystem. The path can be relative or fully-qualified.

This method will extract all entries in the ZipFile to the specified path. If an extraction of a file from the zip archive would overwrite an existing file in the filesystem, the action taken is dictated by the ExtractExistingFile property, which overrides any setting you may have made on individual ZipEntry instances. By default, if you have not set that property on the ZipFile instance, the entry will not be extracted, the existing file will not be overwritten and an exception will be thrown. To change this, set the property, or use the overload that allows you to specify an ExtractExistingFileAction parameter. The action to take when an extract would overwrite an existing file applies to all entries. If you want to set this on a per-entry basis, then you must use one of the ZipEntry.Extract methods. This method will send verbose output messages to the , if it is set on the ZipFile instance. You may wish to take advantage of the ExtractProgress event. About Timestamps: When extracting a file entry from a zip archive, the extracted file gets the last modified time of the entry as stored in the archive. The archive may also store extended file timestamp information, including last accessed and created times. If these are present in the ZipEntry, then the extracted file will also get these times. A Directory entry is somewhat different. It will get the times as described for a file entry, but, if there are file entries in the zip archive that, when extracted, appear in the just-created directory, then when those file entries are extracted, the last modified and last accessed times of the directory will change, as a side effect. The result is that after an extraction of a directory and a number of files within the directory, the last modified and last accessed timestamps on the directory will reflect the time that the last file was extracted into the directory, rather than the time stored in the zip archive for the directory. To compensate, when extracting an archive with ExtractAll, DotNetZip will extract all the file and directory entries as described above, but it will then make a second pass on the directories, and reset the times on the directories to reflect what is stored in the zip archive. This compensation is performed only within the context of an ExtractAll. If you call ZipEntry.Extract on a directory entry, the timestamps on directory in the filesystem will reflect the times stored in the zip. If you then call ZipEntry.Extract on a file entry, which is extracted into the directory, the timestamps on the directory will be updated to the current time. This example extracts all the entries in a zip archive file, to the specified target directory. The extraction will overwrite any existing files silently.


             String TargetDirectory= "unpack";
             using(ZipFile zip= ZipFile.Read(ZipFileToExtract))
             {
                 zip.ExtractExistingFile= ExtractExistingFileAction.OverwriteSilently;
                 zip.ExtractAll(TargetDirectory);
             }


             Dim TargetDirectory As String = "unpack"
             Using zip As ZipFile = ZipFile.Read(ZipFileToExtract)
                 zip.ExtractExistingFile= ExtractExistingFileAction.OverwriteSilently
                 zip.ExtractAll(TargetDirectory)
             End Using

The path to which the contents of the zipfile will be extracted. The path can be relative or fully-qualified.

Extracts all of the items in the zip archive, to the specified path in the filesystem, using the specified behavior when extraction would overwrite an existing file.

This method will extract all entries in the ZipFile to the specified path. For an extraction that would overwrite an existing file, the behavior is dictated by , which overrides any setting you may have made on individual ZipEntry instances. The action to take when an extract would overwrite an existing file applies to all entries. If you want to set this on a per-entry basis, then you must use or one of the similar methods. Calling this method is equivalent to setting the property and then calling . This method will send verbose output messages to the , if it is set on the ZipFile instance. This example extracts all the entries in a zip archive file, to the specified target directory. It does not overwrite any existing files.


             String TargetDirectory= "c:\\unpack";
             using(ZipFile zip= ZipFile.Read(ZipFileToExtract))
             {
               zip.ExtractAll(TargetDirectory, ExtractExistingFileAction.DontOverwrite);
             }


             Dim TargetDirectory As String = "c:\unpack"
             Using zip As ZipFile = ZipFile.Read(ZipFileToExtract)
                 zip.ExtractAll(TargetDirectory, ExtractExistingFileAction.DontOverwrite)
             End Using

The path to which the contents of the zipfile will be extracted. The path can be relative or fully-qualified. The action to take if extraction would overwrite an existing file.

Reads a zip file archive and returns the instance.

The stream is read using the default System.Text.Encoding, which is the IBM437 codepage. Thrown if the ZipFile cannot be read. The implementation of this method relies on System.IO.File.OpenRead, which can throw a variety of exceptions, including specific exceptions if a file is not found, an unauthorized access exception, exceptions for poorly formatted filenames, and so on. The name of the zip archive to open. This can be a fully-qualified or relative pathname. This method has a bunch of interesting overloads. They are all static (Shared in VB). One of them is bound to be right for you. The reason there are so many is that there are a few properties on the ZipFile class that must be set before you read the zipfile in, for them to be useful. The set of overloads covers the most interesting cases. Probably there are still too many, though. The instance read from the zip archive.

Reads a zip file archive and returns the instance, using the specified ReadProgress event handler.

The name of the zip archive to open. This can be a fully-qualified or relative pathname. An event handler for Read operations. The instance read from the zip archive.

Reads a zip file archive using the specified text encoding, and returns the instance.

This version of the method allows the caller to pass in a TextWriter. The ZipFile is read in using the default IBM437 encoding for entries where UTF-8 encoding is not explicitly specified.


             var sw = new System.IO.StringWriter();
             using (ZipFile zip =  ZipFile.Read("PackedDocuments.zip", sw))
             {
               var Threshold = new DateTime(2007,7,4);
               // We cannot remove the entry from the list, within the context of
               // an enumeration of said list.
               // So we add the doomed entry to a list to be removed later.
               // pass 1: mark the entries for removal
               var MarkedEntries = new System.Collections.Generic.List<ZipEntry>();
               foreach (ZipEntry e in zip)
               {
                 if (e.LastModified < Threshold)
                   MarkedEntries.Add(e);
               }
               // pass 2: actually remove the entry.
               foreach (ZipEntry zombie in MarkedEntries)
                  zip.RemoveEntry(zombie);
               zip.Comment = "This archive has been updated.";
               zip.Save();
             }
             // can now use contents of sw, eg store in an audit log


               Dim sw As New System.IO.StringWriter
               Using zip As ZipFile = ZipFile.Read("PackedDocuments.zip", sw)
                   Dim Threshold As New DateTime(2007, 7, 4)
                   ' We cannot remove the entry from the list, within the context of
                   ' an enumeration of said list.
                   ' So we add the doomed entry to a list to be removed later.
                   ' pass 1: mark the entries for removal
                   Dim MarkedEntries As New System.Collections.Generic.List(Of ZipEntry)
                   Dim e As ZipEntry
                   For Each e In zip
                       If (e.LastModified < Threshold) Then
                           MarkedEntries.Add(e)
                       End If
                   Next
                   ' pass 2: actually remove the entry.
                   Dim zombie As ZipEntry
                   For Each zombie In MarkedEntries
                       zip.RemoveEntry(zombie)
                   Next
                   zip.Comment = "This archive has been updated."
                   zip.Save
               End Using
               ' can now use contents of sw, eg store in an audit log

Thrown if the zipfile cannot be read. The implementation of this method relies on System.IO.File.OpenRead, which can throw a variety of exceptions, including specific exceptions if a file is not found, an unauthorized access exception, exceptions for poorly formatted filenames, and so on. The name of the zip archive to open. This can be a fully-qualified or relative pathname. The System.IO.TextWriter to use for writing verbose status messages during operations on the zip archive. A console application may wish to pass System.Console.Out to get messages on the Console. A graphical or headless application may wish to capture the messages in a different TextWriter, such as a System.IO.StringWriter. The instance read from the zip archive.

Reads a zip file archive using the specified text encoding, and the specified ReadProgress event handler, and returns the instance.

Reads a zip file archive using the specified text encoding, and returns the instance.

This version of the method allows the caller to pass in an Encoding. The ZipFile is read in using the specified encoding for entries where UTF-8 encoding is not explicitly specified. This example shows how to read a zip file using the Big-5 Chinese code page (950), and extract each entry in the zip file. For this code to work as desired, the zipfile must have been created using the big5 code page (CP950). This is typical, for example, when using WinRar on a machine with CP950 set as the default code page. In that case, the names of entries within the Zip archive will be stored in that code page, and reading the zip archive must be done using that code page. If the application did not use the correct code page in ZipFile.Read(), then names of entries within the zip archive would not be correctly retrieved.


             using (ZipFile zip = ZipFile.Read(ZipToExtract,
                                               System.Text.Encoding.GetEncoding(950)))
             {
               foreach (ZipEntry e in zip)
               {
                  e.Extract(extractDirectory);
               }
             }


             Using zip As ZipFile = ZipFile.Read(ZipToExtract, System.Text.Encoding.GetEncoding(950))
                 Dim e As ZipEntry
                 For Each e In zip
                  e.Extract(extractDirectory)
                 Next
             End Using

Reads a zip file archive using the specified text encoding and ReadProgress event handler, and returns the instance.

The name of the zip archive to open. This can be a fully-qualified or relative pathname. An event handler for Read operations. The System.Text.Encoding to use when reading in the zip archive. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. The instance read from the zip archive.

Reads a zip file archive using the specified text encoding and the specified TextWriter for status messages, and returns the instance.

This version of the method allows the caller to pass in a TextWriter and an Encoding. The ZipFile is read in using the specified encoding for entries where UTF-8 encoding is not explicitly specified. This example shows how to read a zip file using the Big-5 Chinese code page (950), and extract each entry in the zip file, while sending status messages out to the Console.


             using (ZipFile zip = ZipFile.Read(ZipToExtract,
                                               System.Console.Out,
                                               System.Text.Encoding.GetEncoding(950)))
             {
               foreach (ZipEntry e in zip)
               {
                  e.Extract(extractDirectory);
               }
             }

Reads a zip file archive using the specified text encoding, the specified TextWriter for status messages, and the specified ReadProgress event handler, and returns the instance.

The name of the zip archive to open. This can be a fully-qualified or relative pathname. An event handler for Read operations. The System.IO.TextWriter to use for writing verbose status messages during operations on the zip archive. A console application may wish to pass System.Console.Out to get messages on the Console. A graphical or headless application may wish to capture the messages in a different TextWriter, such as a System.IO.StringWriter. The System.Text.Encoding to use when reading in the zip archive. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. The instance read from the zip archive.

Reads a zip archive from a stream.

This is useful when when the zip archive content is available from an already-open stream. The stream must be open and readable when calling this method. The stream is left open when the reading is completed. Using this overload, the stream is read using the default System.Text.Encoding, which is the IBM437 codepage. If you want to specify the encoding to use when reading the zipfile content, check out the other overloads of the ZipFile constructor. Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. This example shows how to Read zip content from a stream, and extract one entry into a different stream. In this example, the filename "NameOfEntryInArchive.doc", refers only to the name of the entry within the zip archive. A file by that name is not created in the filesystem. The I/O is done strictly with the given streams.


             using (ZipFile zip = ZipFile.Read(InputStream))
             {
                zip.Extract("NameOfEntryInArchive.doc", OutputStream);
             }


             Using zip as ZipFile = ZipFile.Read(InputStream)
                zip.Extract("NameOfEntryInArchive.doc", OutputStream)
             End Using

the stream containing the zip data. an instance of ZipFile

Reads a zip archive from a stream, with a given ReadProgress event handler.

When opening large zip archives, you may want to display a progress bar or other indicator of status progress while reading. This Read() method allows you to specify a ReadProgress Event Handler directly. The stream is read using the default encoding (IBM437). Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. An event handler for Read operations. an instance of ZipFile corresponding to the stream being read.

Reads a zip archive from a stream, using the specified TextWriter for status messages.

This method is useful when when the zip archive content is available from an already-open stream. The stream must be open and readable when calling this method. The stream is left open when the reading is completed. The stream is read using the default System.Text.Encoding, which is the IBM437 codepage. For more information on the encoding, see the property. Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. an instance of ZipFile

Reads a zip archive from a stream, using the specified TextWriter for status messages, and the specified ReadProgress event handler.

The stream is read using the default System.Text.Encoding, which is the IBM437 codepage. For more information on the encoding, see the property. Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. An event handler for Read operations. an instance of ZipFile

Reads a zip archive from a stream, using the specified encoding.

This method is useful when when the zip archive content is available from an already-open stream. The stream must be open and readable when calling this method. The stream is left open when the reading is completed. Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The text encoding to use when reading entries that do not have the UTF-8 encoding bit set. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. See the property for more information. an instance of ZipFile

Reads a zip archive from a stream, using the specified encoding, and and the specified ReadProgress event handler.

Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The text encoding to use when reading entries that do not have the UTF-8 encoding bit set. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. See the property for more information. An event handler for Read operations. an instance of ZipFile

Reads a zip archive from a stream, using the specified text Encoding and the specified TextWriter for status messages.

This method is useful when when the zip archive content is available from an already-open stream. The stream must be open and readable when calling this method. The stream is left open when the reading is completed. Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. The text encoding to use when reading entries that do not have the UTF-8 encoding bit set. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. See the property for more information. an instance of ZipFile

Reads a zip archive from a stream, using the specified text Encoding, the specified TextWriter for status messages, and the specified ReadProgress event handler.

Reading of zip content begins at the current position in the stream. This means if you have a stream that concatenates regular data and zip data, if you position the open, readable stream at the start of the zip data, you will be able to read the zip archive using this constructor, or any of the ZipFile constructors that accept a as input. Some examples of where this might be useful: the zip content is concatenated at the end of a regular EXE file, as some self-extracting archives do. (Note: SFX files produced by DotNetZip do not work this way). Another example might be a stream being read from a database, where the zip content is embedded within an aggregate stream of data. the stream containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. The text encoding to use when reading entries that do not have the UTF-8 encoding bit set. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. See the property for more information. An event handler for Read operations. an instance of ZipFile

Reads a zip archive from a byte array.

This is useful when the data for the zipfile is contained in a byte array, for example, downloaded from an FTP server without being saved to a filesystem. The byte array containing the zip data. (I don't know why, but sometimes the compiled helpfile (.chm) indicates a 2d array when it is just one-dimensional. This is a one-dimensional array.) an instance of ZipFile. The name on the ZipFile will be null (Nothing in VB).

Reads a zip archive from a byte array, using the given StatusMessageWriter.

This method is useful when the data for the zipfile is contained in a byte array, for example when retrieving the data from a database or other non-filesystem store. The default Text Encoding (IBM437) is used to read the zipfile data. the byte array containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. an instance of ZipFile. The name is set to null (Nothing in VB).

Reads a zip archive from a byte array, using the given StatusMessageWriter and text Encoding.

This method is useful when the data for the zipfile is contained in a byte array, for example when retrieving the data from a database or other non-filesystem store. the byte array containing the zip data. The System.IO.TextWriter to which verbose status messages are written during operations on the ZipFile. For example, in a console application, System.Console.Out works, and will get a message for each entry added to the ZipFile. If the TextWriter is null, no verbose messages are written. The text encoding to use when reading entries that do not have the UTF-8 encoding bit set. Be careful specifying the encoding. If the value you use here is not the same as the Encoding used when the zip archive was created (possibly by a different archiver) you will get unexpected results and possibly exceptions. See the property for more information. an instance of ZipFile. The name is set to null (Nothing in VB).

Checks the given file to see if it appears to be a valid zip file.

Calling this method is equivalent to calling with the testExtract parameter set to false. The file to check. true if the file appears to be a zip file.

Checks a file to see if it is a valid zip file.

This method opens the specified zip file, reads in the zip archive, verifying the ZIP metadata as it reads. If everything succeeds, then the method returns true. If anything fails - for example if an incorrect signature or CRC is found, indicating a corrupt file, the the method returns false. This method also returns false for a file that does not exist. If is true, as part of its check, this method reads in the content for each entry, expands it, and checks CRCs. This provides an additional check beyond verifying the zip header and directory data. If is true, and if any of the zip entries are protected with a password, this method will return false. If you want to verify a ZipFile that has entries which are protected with a password, you will need to do that manually. The zip file to check. true if the caller wants to extract each entry. true if the file contains a valid zip file.

Checks a stream to see if it contains a valid zip archive.

This method reads the zip archive contained in the specified stream, verifying the ZIP metadata as it reads. If testExtract is true, this method also extracts each entry in the archive, dumping all the bits into . If everything succeeds, then the method returns true. If anything fails - for example if an incorrect signature or CRC is found, indicating a corrupt file, the the method returns false. This method also returns false for a file that does not exist. If testExtract is true, this method reads in the content for each entry, expands it, and checks CRCs. This provides an additional check beyond verifying the zip header data. If testExtract is true, and if any of the zip entries are protected with a password, this method will return false. If you want to verify a ZipFile that has entries which are protected with a password, you will need to do that manually. The stream to check. true if the caller wants to extract each entry. true if the stream contains a valid zip archive.

Indicates whether to perform a full scan of the zip file when reading it.

You almost never want to use this property. When reading a zip file, if this flag is true (True in VB), the entire zip archive will be scanned and searched for entries. For large archives, this can take a very, long time. The much more efficient default behavior is to read the zip directory, which is stored at the end of the zip file. But, in some cases the directory is corrupted and you need to perform a full scan of the zip file to determine the contents of the zip file. This property lets you do that, when necessary. This flag is effective only when calling . Normally you would read a ZipFile with the static ZipFile.Read method. But you can't set the FullScan property on the ZipFile instance when you use a static factory method like ZipFile.Read. This example shows how to read a zip file using the full scan approach, and then save it, thereby producing a corrected zip file.


             using (var zip = new ZipFile())
             {
                 zip.FullScan = true;
                 zip.Initialize(zipFileName);
                 zip.Save(newName);
             }


             Using zip As New ZipFile
                 zip.FullScan = True
                 zip.Initialize(zipFileName)
                 zip.Save(newName)
             End Using

Whether to sort the ZipEntries before saving the file.

The default is false. If you have a large number of zip entries, the sort alone can consume significant time.


             using (var zip = new ZipFile())
             {
                 zip.AddFiles(filesToAdd);
                 zip.SortEntriesBeforeSaving = true;
                 zip.Save(name);
             }


             Using zip As New ZipFile
                 zip.AddFiles(filesToAdd)
                 zip.SortEntriesBeforeSaving = True
                 zip.Save(name)
             End Using

Indicates whether NTFS Reparse Points, like junctions, should be traversed during calls to AddDirectory().

By default, calls to AddDirectory() will traverse NTFS reparse points, like mounted volumes, and directory junctions. An example of a junction is the "My Music" directory in Windows Vista. In some cases you may not want DotNetZip to traverse those directories. In that case, set this property to false.


             using (var zip = new ZipFile())
             {
                 zip.AddDirectoryWillTraverseReparsePoints = false;
                 zip.AddDirectory(dirToZip,"fodder");
                 zip.Save(zipFileToCreate);
             }

Size of the IO buffer used while saving.

First, let me say that you really don't need to bother with this. It is here to allow for optimizations that you probably won't make! It will work fine if you don't set or get this property at all. Ok? Now that we have that out of the way, the fine print: This property affects the size of the buffer that is used for I/O for each entry contained in the zip file. When a file is read in to be compressed, it uses a buffer given by the size here. When you update a zip file, the data for unmodified entries is copied from the first zip file to the other, through a buffer given by the size here. Changing the buffer size affects a few things: first, for larger buffer sizes, the memory used by the ZipFile, obviously, will be larger during I/O operations. This may make operations faster for very much larger files. Last, for any given entry, when you use a larger buffer there will be fewer progress events during I/O operations, because there's one progress event generated for each time the buffer is filled and then emptied. The default buffer size is 8k. Increasing the buffer size may speed things up as you compress larger files. But there are no hard-and-fast rules here, eh? You won't know til you test it. And there will be a limit where ever larger buffers actually slow things down. So as I said in the beginning, it's probably best if you don't set or get this property at all. This example shows how you might set a large buffer size for efficiency when dealing with zip entries that are larger than 1gb.


             using (ZipFile zip = new ZipFile())
             {
                 zip.SaveProgress += this.zip1_SaveProgress;
                 zip.AddDirectory(directoryToZip, "");
                 zip.UseZip64WhenSaving = Zip64Option.Always;
                 zip.BufferSize = 65536*8; // 65536 * 8 = 512k
                 zip.Save(ZipFileToCreate);
             }

Size of the work buffer to use for the ZLIB codec during compression.

Setting this affects the performance and memory efficiency of compression and decompression. For larger files, setting this to a larger size may improve performance, but the exact numbers vary depending on available memory, and a bunch of other variables. I don't have good firm recommendations on how to set it. You'll have to test it yourself. Or just leave it alone and accept the default.

Indicates whether extracted files should keep their paths as stored in the zip archive.

This property affects Extraction. It is not used when creating zip archives. With this property set to false, the default, extracting entries from a zip file will create files in the filesystem that have the full path associated to the entry within the zip file. With this property set to true, extracting entries from the zip file results in files with no path: the folders are "flattened." An example: suppose the zip file contains entries /directory1/file1.txt and /directory2/file2.txt. With FlattenFoldersOnExtract set to false, the files created will be \directory1\file1.txt and \directory2\file2.txt. With the property set to true, the files created are file1.txt and file2.txt.

The compression strategy to use for all entries.

Set the Strategy used by the ZLIB-compatible compressor, when compressing entries. Different compression strategies work better on different sorts of data. The strategy parameter can affect the compression ratio and the speed of compression but not the correctness of the compresssion. For more information see Ionic.Zlib.CompressionStrategy.

The name of the ZipFile, on disk.

When the ZipFile instance was created by reading an archive using one of the ZipFile.Read methods, this property represents the name of the zip file that was read. When the ZipFile instance was created by using the no-argument constructor, this value is null (Nothing in VB). If you use the no-argument constructor, and you then explicitly set this property, when you call , this name will specify the name of the zip file created. Doing so is equivalent to calling . When instantiating a ZipFile by reading from a stream or byte array, the Name property remains null. When saving to a stream, the Name property is implicitly set to null.

Sets the compression level to be used for entries subsequently added to the zip archive.

Varying the compression level used on entries can affect the size-vs-speed tradeoff when compression and decompressing data streams or files. As with some other properties on the ZipFile class, like , , and , setting this property on a ZipFile instance will cause the specified CompressionLevel to be used on all items that are subsequently added to the ZipFile instance. If you set this property after you have added items to the ZipFile, but before you have called Save(), those items will not use the specified compression level. If you do not set this property, the default compression level is used, which normally gives a good balance of compression efficiency and compression speed. In some tests, using BestCompression can double the time it takes to compress, while delivering just a small increase in compression efficiency. This behavior will vary with the type of data you compress. If you are in doubt, just leave this setting alone, and accept the default.

A comment attached to the zip archive.

This property is read/write. It allows the application to specify a comment for the ZipFile, or read the comment for the ZipFile. After setting this property, changes are only made permanent when you call a Save() method. According to PKWARE's zip specification, the comment is not encrypted, even if there is a password set on the zip file. The zip spec does not describe how to encode the comment string in a code page other than IBM437. Therefore, for "compliant" zip tools and libraries, comments will use IBM437. However, there are situations where you want an encoded Comment, for example using code page 950 "Big-5 Chinese". DotNetZip will encode the comment in the code page specified by , at the time of the call to ZipFile.Save(). When creating a zip archive using this library, it is possible to change the value of between each entry you add, and between adding entries and the call to Save(). Don't do this. It will likely result in a zip file that is not readable by any tool or application. For best interoperability, leave alone, or specify it only once, before adding any entries to the ZipFile instance.

Specifies whether the Creation, Access, and Modified times for entries added to the zip file will be emitted in "Windows format" when the zip archive is saved.

An application creating a zip archive can use this flag to explicitly specify that the file times for the entries should or should not be stored in the zip archive in the format used by Windows. By default this flag is true, meaning the Windows-format times are stored in the zip archive. When adding an entry from a file or directory, the Creation (), Access (), and Modified () times for the given entry are automatically set from the filesystem values. When adding an entry from a stream or string, all three values are implicitly set to DateTime.Now. Applications can also explicitly set those times by calling . PKWARE's zip specification describes multiple ways to format these times in a zip file. One is the format Windows applications normally use: 100ns ticks since January 1, 1601 UTC. The other is a format Unix applications typically use: seconds since January 1, 1970 UTC. Each format can be stored in an "extra field" in the zip entry when saving the zip archive. The former uses an extra field with a Header Id of 0x000A, while the latter uses a header ID of 0x5455, although you probably don't need to know that. Not all tools and libraries can interpret these fields. Windows compressed folders is one that can read the Windows Format timestamps, while I believe the Infozip tools can read the Unix format timestamps. Some tools and libraries may be able to read only one or the other. DotNetZip can read or write times in either or both formats. The times stored are taken from , , and . The value set here applies to all entries subsequently added to the ZipFile. This property is not mutually exclusive of the property. It is possible and legal and valid to produce a zip file that contains timestamps encoded in the Unix format as well as in the Windows format, in addition to the LastModified time attached to each entry in the archive, a time that is always stored in "DOS format". And, notwithstanding the names PKWare uses for these time formats, any of them can be read and written by any computer, on any operating system. But, there are no guarantees that a program running on Mac or Linux will gracefully handle a zip file with "Windows" formatted times, or that an application that does not use DotNetZip but runs on Windows will be able to handle file times in Unix format. When in doubt, test. Sorry, I haven't got a complete list of tools and which sort of timestamps they can use and will tolerate. If you get any good information and would like to pass it on, please do so and I will include that information in this documentation. This example shows how to save a zip file that contains file timestamps in a format normally used by Unix.


             using (var zip = new ZipFile())
             {
                 // produce a zip file the Mac will like
                 zip.EmitTimesInWindowsFormatWhenSaving = false;
                 zip.EmitTimesInUnixFormatWhenSaving = true;
                 zip.AddDirectory(directoryToZip, "files");
                 zip.Save(outputFile);
             }


             Using zip As New ZipFile
                 '' produce a zip file the Mac will like
                 zip.EmitTimesInWindowsFormatWhenSaving = False
                 zip.EmitTimesInUnixFormatWhenSaving = True
                 zip.AddDirectory(directoryToZip, "files")
                 zip.Save(outputFile)
             End Using

Specifies whether the Creation, Access, and Modified times for entries added to the zip file will be emitted in "Unix(tm) format" when the zip archive is saved.

An application creating a zip archive can use this flag to explicitly specify that the file times for the entries should or should not be stored in the zip archive in the format used by Unix. By default this flag is false, meaning the Unix-format times are not stored in the zip archive. When adding an entry from a file or directory, the Creation (), Access (), and Modified () times for the given entry are automatically set from the filesystem values. When adding an entry from a stream or string, all three values are implicitly set to DateTime.Now. Applications can also explicitly set those times by calling . PKWARE's zip specification describes multiple ways to format these times in a zip file. One is the format Windows applications normally use: 100ns ticks since January 1, 1601 UTC. The other is a format Unix applications typically use: seconds since January 1, 1970 UTC. Each format can be stored in an "extra field" in the zip entry when saving the zip archive. The former uses an extra field with a Header Id of 0x000A, while the latter uses a header ID of 0x5455, although you probably don't need to know that. Not all tools and libraries can interpret these fields. Windows compressed folders is one that can read the Windows Format timestamps, while I believe the Infozip tools can read the Unix format timestamps. Some tools and libraries may be able to read only one or the other. DotNetZip can read or write times in either or both formats. The times stored are taken from , , and . This property is not mutually exclusive of the property. It is possible and legal and valid to produce a zip file that contains timestamps encoded in the Unix format as well as in the Windows format, in addition to the LastModified time attached to each entry in the zip archive, a time that is always stored in "DOS format". And, notwithstanding the names PKWare uses for these time formats, any of them can be read and written by any computer, on any operating system. But, there are no guarantees that a program running on Mac or Linux will gracefully handle a zip file with "Windows" formatted times, or that an application that does not use DotNetZip but runs on Windows will be able to handle file times in Unix format. When in doubt, test. Sorry, I haven't got a complete list of tools and which sort of timestamps they can use and will tolerate. If you get any good information and would like to pass it on, please do so and I will include that information in this documentation.

Indicates whether verbose output is sent to the during AddXxx() and ReadXxx() operations.

This is a synthetic property. It returns true if the is non-null.

Indicates whether to perform case-sensitive matching on the filename when retrieving entries in the zipfile via the string-based indexer.

The default value is false, which means don't do case-sensitive matching. In other words, retrieving zip["ReadMe.Txt"] is the same as zip["readme.txt"]. It really makes sense to set this to true only if you are not running on Windows, which has case-insensitive filenames. But since this library is not built for non-Windows platforms, in most cases you should just leave this property alone.

Indicates whether to encode entry filenames and entry comments using Unicode (UTF-8).

The PKWare zip specification provides for encoding file names and file comments in either the IBM437 code page, or in UTF-8. This flag selects the encoding according to that specification. By default, this flag is false, and filenames and comments are encoded into the zip file in the IBM437 codepage. Setting this flag to true will specify that filenames and comments that cannot be encoded with IBM437 will be encoded with UTF-8. Zip files created with strict adherence to the PKWare specification with respect to UTF-8 encoding can contain entries with filenames containing any combination of Unicode characters, including the full range of characters from Chinese, Latin, Hebrew, Greek, Cyrillic, and many other alphabets. However, because at this time, the UTF-8 portion of the PKWare specification is not broadly supported by other zip libraries and utilities, such zip files may not be readable by your favorite zip tool or archiver. In other words, interoperability will decrease if you set this flag to true. In particular, Zip files created with strict adherence to the PKWare specification with respect to UTF-8 encoding will not work well with Explorer in Windows XP or Windows Vista, because Windows compressed folders, as far as I know, do not support UTF-8 in zip files. Vista can read the zip files, but shows the filenames incorrectly. Unpacking from Windows Vista Explorer will result in filenames that have rubbish characters in place of the high-order UTF-8 bytes. Also, zip files that use UTF-8 encoding will not work well with Java applications that use the java.util.zip classes, as of v5.0 of the Java runtime. The Java runtime does not correctly implement the PKWare specification in this regard. As a result, we have the unfortunate situation that "correct" behavior by the DotNetZip library with regard to Unicode encoding of filenames during zip creation will result in zip files that are readable by strictly compliant and current tools (for example the most recent release of the commercial WinZip tool); but these zip files will not be readable by various other tools or libraries, including Windows Explorer. The DotNetZip library can read and write zip files with UTF8-encoded entries, according to the PKware spec. If you use DotNetZip for both creating and reading the zip file, and you use UTF-8, there will be no loss of information in the filenames. For example, using a self-extractor created by this library will allow you to unpack files correctly with no loss of information in the filenames. If you do not set this flag, it will remain false. If this flag is false, your ZipFile will encode all filenames and comments using the IBM437 codepage. This can cause "loss of information" on some filenames, but the resulting zipfile will be more interoperable with other utilities. As an example of the loss of information, diacritics can be lost. The o-tilde character will be down-coded to plain o. The c with a cedilla (Unicode 0xE7) used in Portugese will be downcoded to a c. Likewise, the O-stroke character (Unicode 248), used in Danish and Norwegian, will be down-coded to plain o. Chinese characters cannot be represented in codepage IBM437; when using the default encoding, Chinese characters in filenames will be represented as ?. These are all examples of "information loss". The loss of information associated to the use of the IBM437 encoding is inconvenient, and can also lead to runtime errors. For example, using IBM437, any sequence of 4 Chinese characters will be encoded as ????. If your application creates a ZipFile, then adds two files, each with names of four Chinese characters each, this will result in a duplicate filename exception. In the case where you add a single file with a name containing four Chinese characters, calling Extract() on the entry that has question marks in the filename will result in an exception, because the question mark is not legal for use within filenames on Windows. These are just a few examples of the problems associated to loss of information. This flag is independent of the encoding of the content within the entries in the zip file. Think of the zip file as a container - it supports an encoding. Within the container are other "containers" - the file entries themselves. The encoding within those entries is independent of the encoding of the zip archive container for those entries. Rather than specify the encoding in a binary fashion using this flag, an application can specify an arbitrary encoding via the property. Setting the encoding explicitly when creating zip archives will result in non-compliant zip files that, curiously, are fairly interoperable. The challenge is, the PKWare specification does not provide for a way to specify that an entry in a zip archive uses a code page that is neither IBM437 nor UTF-8. Therefore if you set the encoding explicitly when creating a zip archive, you must take care upon reading the zip archive to use the same code page. If you get it wrong, the behavior is undefined and may result in incorrect filenames, exceptions, stomach upset, hair loss, and acne.

Specify whether to use ZIP64 extensions when saving a zip archive.

When creating a zip file, the default value for the property is . is safest, in the sense that you will not get an Exception if a pre-ZIP64 limit is exceeded. You may set the property at any time before calling Save(). When reading a zip file via the Zipfile.Read() method, DotNetZip will properly read ZIP64-endowed zip archives, regardless of the value of this property. DotNetZip will always read ZIP64 archives. This property governs only whether DotNetZip will write them. Therefore, when updating archives, be careful about setting this property after reading an archive that may use ZIP64 extensions. An interesting question is, if you have set this property to AsNecessary, and then successfully saved, does the resulting archive use ZIP64 extensions or not? To learn this, check the property, after calling Save(). Have you thought about donating?

Indicates whether the archive requires ZIP64 extensions.

This property is null (or Nothing in VB) if the archive has not been saved, and there are fewer than 65334 ZipEntry items contained in the archive. The Value is true if any of the following four conditions holds: the uncompressed size of any entry is larger than 0xFFFFFFFF; the compressed size of any entry is larger than 0xFFFFFFFF; the relative offset of any entry within the zip archive is larger than 0xFFFFFFFF; or there are more than 65534 entries in the archive. (0xFFFFFFFF = 4,294,967,295). The result may not be known until a Save() is attempted on the zip archive. The Value of this property may be set only AFTER one of the Save() methods has been called. If none of the four conditions holds, and the archive has been saved, then the Value is false. A Value of false does not indicate that the zip archive, as saved, does not use ZIP64. It merely indicates that ZIP64 is not required. An archive may use ZIP64 even when not required if the property is set to , or if the property is set to and the output stream was not seekable. Use the property to determine if the most recent Save() method resulted in an archive that utilized the ZIP64 extensions.

Indicates whether the most recent Save() operation used ZIP64 extensions.

The use of ZIP64 extensions within an archive is not always necessary, and for interoperability concerns, it may be desired to NOT use ZIP64 if possible. The property can be set to use ZIP64 extensions only when necessary. In those cases, Sometimes applications want to know whether a Save() actually used ZIP64 extensions. Applications can query this read-only property to learn whether ZIP64 has been used in a just-saved ZipFile. The value is null (or Nothing in VB) if the archive has not been saved. Non-null values (HasValue is true) indicate whether ZIP64 extensions were used during the most recent Save() operation. The ZIP64 extensions may have been used as required by any particular entry because of its uncompressed or compressed size, or because the archive is larger than 4294967295 bytes, or because there are more than 65534 entries in the archive, or because the UseZip64WhenSaving property was set to , or because the UseZip64WhenSaving property was set to and the output stream was not seekable. The value of this property does not indicate the reason the ZIP64 extensions were used.

Indicates whether the most recent Read() operation read a zip file that uses ZIP64 extensions.

This property will return null (Nothing in VB) if you've added an entry after reading the zip file.

The text encoding to use when writing new entries to the ZipFile, for those entries that cannot be encoded with the default (IBM437) encoding; or, the text encoding that was used when reading the entries from the ZipFile.

In its zip specification, PKWare describes two options for encoding filenames and comments: using IBM437 or UTF-8. But, some archiving tools or libraries do not follow the specification, and instead encode characters using the system default code page. For example, WinRAR when run on a machine in Shanghai may encode filenames with the Big-5 Chinese (950) code page. This behavior is contrary to the Zip specification, but it occurs anyway. When using DotNetZip to write zip archives that will be read by one of these other archivers, set this property to specify the code page to use when encoding the and for each ZipEntry in the zip file, for values that cannot be encoded with the default codepage for zip files, IBM437. This is why this property is "provisional". In all cases, IBM437 is used where possible, in other words, where no loss of data would result. It is possible, therefore, to have a given entry with a Comment encoded in IBM437 and a FileName encoded with the specified "provisional" codepage. Be aware that a zip file created after you've explicitly set the property to a value other than IBM437 may not be compliant to the PKWare specification, and may not be readable by compliant archivers. On the other hand, many (most?) archivers are non-compliant and can read zip files created in arbitrary code pages. The trick is to use or specify the proper codepage when reading the zip. When creating a zip archive using this library, it is possible to change the value of between each entry you add, and between adding entries and the call to Save(). Don't do this. It will likely result in a zipfile that is not readable. For best interoperability, either leave alone, or specify it only once, before adding any entries to the ZipFile instance. There is one exception to this recommendation, described later. When using an arbitrary, non-UTF8 code page for encoding, there is no standard way for the creator application - whether DotNetZip, WinZip, WinRar, or something else - to formally specify in the zip file which codepage has been used for the entries. As a result, readers of zip files are not able to inspect the zip file and determine the codepage that was used for the entries contained within it. It is left to the application or user to determine the necessary codepage when reading zip files encoded this way. In other words, if you explicitly specify the codepage when you create the zipfile, you must explicitly specify the same codepage when reading the zipfile. The way you specify the code page to use when reading a zip file varies depending on the tool or library you use to read the zip. In DotNetZip, you use a ZipFile.Read() method that accepts an encoding parameter. It isn't possible with Windows Explorer, as far as I know, to specify an explicit codepage to use when reading a zip. If you use an incorrect codepage when reading a zipfile, you will get entries with filenames that are incorrect, and the incorrect filenames may even contain characters that are not legal for use within filenames in Windows. Extracting entries with illegal characters in the filenames will lead to exceptions. It's too bad, but this is just the way things are with code pages in zip files. Caveat Emptor. Example: Suppose you create a zipfile that contains entries with filenames that have Danish characters. If you use equal to "iso-8859-1" (cp 28591), the filenames will be correctly encoded in the zip. But, to read that zipfile correctly, you have to specify the same codepage at the time you read it. If try to read that zip file with Windows Explorer or another application that is not flexible with respect to the codepage used to decode filenames in zipfiles, you will get a filename like "Inf°.txt". When using DotNetZip to read a zip archive, and the zip archive uses an arbitrary code page, you must specify the encoding to use before or when the Zipfile is READ. This means you must use a ZipFile.Read() method that allows you to specify a System.Text.Encoding parameter. Setting the ProvisionalAlternateEncoding property after your application has read in the zip archive will not affect the entry names of entries that have already been read in. And now, the exception to the rule described above. One strategy for specifying the code page for a given zip file is to describe the code page in a human-readable form in the Zip comment. For example, the comment may read "Entries in this archive are encoded in the Big5 code page". For maximum interoperability, the zip comment in this case should be encoded in the default, IBM437 code page. In this case, the zip comment is encoded using a different page than the filenames. To do this, Specify ProvisionalAlternateEncoding to your desired region-specific code page, once before adding any entries, and then reset ProvisionalAlternateEncoding to IBM437 before setting the property and calling Save(). This example shows how to read a zip file using the Big-5 Chinese code page (950), and extract each entry in the zip file. For this code to work as desired, the Zipfile must have been created using the big5 code page (CP950). This is typical, for example, when using WinRar on a machine with CP950 set as the default code page. In that case, the names of entries within the Zip archive will be stored in that code page, and reading the zip archive must be done using that code page. If the application did not use the correct code page in ZipFile.Read(), then names of entries within the zip archive would not be correctly retrieved.


             using (var zip = ZipFile.Read(zipFileName, System.Text.Encoding.GetEncoding("big5")))
             {
                 // retrieve and extract an entry using a name encoded with CP950
                 zip[MyDesiredEntry].Extract("unpack");
             }


             Using zip As ZipFile = ZipFile.Read(ZipToExtract, System.Text.Encoding.GetEncoding("big5"))
                 ' retrieve and extract an entry using a name encoded with CP950
                 zip(MyDesiredEntry).Extract("unpack")
             End Using

DefaultEncoding

Gets or sets the TextWriter to which status messages are delivered for the instance.

If the TextWriter is set to a non-null value, then verbose output is sent to the TextWriter during Add, Read, Save and Extract operations. Typically, console applications might use Console.Out and graphical or headless applications might use a System.IO.StringWriter. The output of this is suitable for viewing by humans. In this example, a console application instantiates a ZipFile, then sets the StatusMessageTextWriter to Console.Out. At that point, all verbose status messages for that ZipFile are sent to the console.


             using (ZipFile zip= ZipFile.Read(FilePath))
             {
               zip.StatusMessageTextWriter= System.Console.Out;
               // messages are sent to the console during extraction
               zip.ExtractAll();
             }


             Using zip As ZipFile = ZipFile.Read(FilePath)
               zip.StatusMessageTextWriter= System.Console.Out
               'Status Messages will be sent to the console during extraction
               zip.ExtractAll()
             End Using

In this example, a Windows Forms application instantiates a ZipFile, then sets the StatusMessageTextWriter to a StringWriter. At that point, all verbose status messages for that ZipFile are sent to the StringWriter.


             var sw = new System.IO.StringWriter();
             using (ZipFile zip= ZipFile.Read(FilePath))
             {
               zip.StatusMessageTextWriter= sw;
               zip.ExtractAll();
             }
             Console.WriteLine("{0}", sw.ToString());


             Dim sw as New System.IO.StringWriter
             Using zip As ZipFile = ZipFile.Read(FilePath)
               zip.StatusMessageTextWriter= sw
               zip.ExtractAll()
             End Using
             'Status Messages are now available in sw

Gets or sets the name for the folder to store the temporary file this library writes when saving a zip archive.

This library will create a temporary file when saving a Zip archive to a file. This file is written when calling one of the Save() methods that does not save to a stream, or one of the SaveSelfExtractor() methods. By default, the library will create the temporary file in the directory specified for the file itself, via the property or via the method. Setting this property allows applications to override this default behavior, so that the library will create the temporary file in the specified folder. For example, to have the library create the temporary file in the current working directory, regardless where the ZipFile is saved, specfy ".". To revert to the default behavior, set this property to null (Nothing in VB). When setting the property to a non-null value, the folder specified must exist; if it does not an exception is thrown. The application should have write and delete permissions on the folder. The permissions are not explicitly checked ahead of time; if the application does not have the appropriate rights, an exception will be thrown at the time Save() is called. There is no temporary file created when reading a zip archive. When saving to a Stream, there is no temporary file created. For example, if the application is an ASP.NET application and calls Save() specifying the Response.OutputStream as the output stream, there is no temporary file created. Thrown when setting the property if the directory does not exist.

Sets the password to be used on the ZipFile instance.

When writing a zip archive, this password is applied to the entries, not to the zip archive itself. It applies to any ZipEntry subsequently added to the ZipFile, using one of the AddFile, AddDirectory, AddEntry, or AddItem methods, etc. When reading a zip archive, this property applies to any entry subsequently extracted from the ZipFile using one of the Extract methods on the ZipFile class. When writing a zip archive, keep this in mind: though the password is set on the ZipFile object, according to the Zip spec, the "directory" of the archive - in other words the list of entries or files contained in the archive - is not encrypted with the password, or protected in any way. If you set the Password property, the password actually applies to individual entries that are added to the archive, subsequent to the setting of this property. The list of filenames in the archive that is eventually created will appear in clear text, but the contents of the individual files are encrypted. This is how Zip encryption works. One simple way around this limitation is to simply double-wrap sensitive filenames: Store the files in a zip file, and then store that zip file within a second, "outer" zip file. If you apply a password to the outer zip file, then readers will be able to see that the outer zip file contains an inner zip file. But readers will not be able to read the directory or file list of the inner zip file. If you set the password on the ZipFile, and then add a set of files to the archive, then each entry is encrypted with that password. You may also want to change the password between adding different entries. If you set the password, add an entry, then set the password to null (Nothing in VB), and add another entry, the first entry is encrypted and the second is not. If you call AddFile(), then set the Password property, then call ZipFile.Save, the file added will not be password-protected, and no warning will be generated. When setting the Password, you may also want to explicitly set the property, to specify how to encrypt the entries added to the ZipFile. If you set the Password to a non-null value and do not set , then PKZip 2.0 ("Weak") encryption is used. This encryption is relatively weak but is very interoperable. If you set the password to a null value (Nothing in VB), Encryption is reset to None. All of the preceding applies to writing zip archives, in other words when you use one of the Save methods. To use this property when reading or an existing ZipFile, do the following: set the Password property on the ZipFile, then call one of the Extract() overloads on the . In this case, the entry is extracted using the Password that is specified on the ZipFile instance. If you have not set the Password property, then the password is null, and the entry is extracted with no password. If you set the Password property on the ZipFile, then call Extract() an entry that has not been encrypted with a password, the password is not used for that entry, and the ZipEntry is extracted as normal. In other words, the password is used only if necessary. The class also has a Password property. It takes precedence over this property on the ZipFile. Typically, you would use the per-entry Password when most entries in the zip archive use one password, and a few entries use a different password. If all entries in the zip file use the same password, then it is simpler to just set this property on the ZipFile itself, whether creating a zip archive or extracting a zip archive. This example creates a zip file, using password protection for the entries, and then extracts the entries from the zip file. When creating the zip file, the Readme.txt file is not protected with a password, but the other two are password-protected as they are saved. During extraction, each file is extracted with the appropriate password.


             // create a file with encryption
             using (ZipFile zip = new ZipFile())
             {
                 zip.AddFile("ReadMe.txt");
                 zip.Password= "!Secret1";
                 zip.AddFile("MapToTheSite-7440-N49th.png");
                 zip.AddFile("2008-Regional-Sales-Report.pdf");
                 zip.Save("EncryptedArchive.zip");
             }
            
             // extract entries that use encryption
             using (ZipFile zip = ZipFile.Read("EncryptedArchive.zip"))
             {
                 zip.Password= "!Secret1";
                 zip.ExtractAll("extractDir");
             }


             Using zip As New ZipFile
                 zip.AddFile("ReadMe.txt")
                 zip.Password = "123456!"
                 zip.AddFile("MapToTheSite-7440-N49th.png")
                 zip.Password= "!Secret1";
                 zip.AddFile("2008-Regional-Sales-Report.pdf")
                 zip.Save("EncryptedArchive.zip")
             End Using
            
            
             ' extract entries that use encryption
             Using (zip as ZipFile = ZipFile.Read("EncryptedArchive.zip"))
                 zip.Password= "!Secret1"
                 zip.ExtractAll("extractDir")
             End Using

ZipFile.Encryption ZipEntry.Password

The action the library should take when extracting a file that already exists.

The action the library should take when an error is encountered while opening or reading files as they are saved into a zip archive.

Errors can occur as a file is being saved to the zip archive. For example, the File.Open may fail, or a File.Read may fail, because of lock conflicts or other reasons. The first problem might occur after having called AddDirectory() on a directory that contains a Clipper .dbf file; the file is locked by Clipper and cannot be opened for read by another process. An example of the second problem might occur when trying to zip a .pst file that is in use by Microsoft Outlook. Outlook locks a range on the file, which allows other processes to open the file, but not read it in its entirety. This property tells DotNetZip what you would like to do in the case of these errors. The primary options are: ZipErrorAction.Throw to throw an exception (this is the default behavior if you don't set this property); ZipErrorAction.Skip to Skip the file for which there was an error and continue saving; ZipErrorAction.Retry to Retry the entry that caused the problem; or ZipErrorAction.InvokeErrorEvent to invoke an event handler. This property is implicitly set to ZipErrorAction.InvokeErrorEvent if you add a handler to the event. If you set this property to something other than ZipErrorAction.InvokeErrorEvent, then the ZipError event is implicitly cleared. What it means is you can set one or the other (or neither), depending on what you want, but you never need to set both. As with some other properties on the ZipFile class, like , , and , setting this property on a ZipFile instance will cause the specified ZipErrorAction to be used on all items that are subsequently added to the ZipFile instance. If you set this property after you have added items to the ZipFile, but before you have called Save(), those items will not use the specified error handling action. If you want to handle any errors that occur with any entry in the zip file in the same way, then set this property once, before adding any entries to the zip archive. If you set this property to ZipErrorAction.Skip and you'd like to learn which files may have been skipped after a Save(), you can set the on the ZipFile before calling Save(). A message will be emitted into that writer for each skipped file, if any. This example shows how to tell DotNetZip to skip any files for which an error is generated during the Save().


             Public Sub SaveZipFile()
                 Dim SourceFolder As String = "fodder"
                 Dim DestFile As String =  "eHandler.zip"
                 Dim sw as New StringWriter
                 Using zipArchive As ZipFile = New ZipFile
                     ' Tell DotNetZip to skip any files for which it encounters an error
                     zipArchive.ZipErrorAction = ZipErrorAction.Skip
                     zipArchive.StatusMessageTextWriter = sw
                     zipArchive.AddDirectory(SourceFolder)
                     zipArchive.Save(DestFile)
                 End Using
                 ' examine sw here to see any messages
             End Sub

The Encryption to use for entries added to the ZipFile.

Set this when creating a zip archive, or when updating a zip archive. The specified Encryption is applied to the entries subsequently added to the ZipFile instance. Applications do not need to set the Encryption property when reading or extracting a zip archive. If you set this to something other than EncryptionAlgorithm.None, you will also need to set the . As with some other properties on the ZipFile class, like and , setting this property on a ZipFile instance will cause the specified EncryptionAlgorithm to be used on all items that are subsequently added to the ZipFile instance. In other words, if you set this property after you have added items to the ZipFile, but before you have called Save(), those items will not be encrypted or protected with a password in the resulting zip archive. To get a zip archive with encrypted entries, set this property, along with the property, before calling AddFile, AddItem, or AddDirectory (etc.) on the ZipFile instance. If you read a ZipFile, you can modify the Encryption on an encrypted entry, only by setting the Encryption property on the ZipEntry itself. Setting the Encryption property on the ZipFile, once it has been created via a call to ZipFile.Read(), does not affect entries that were previously read. For example, suppose you read a ZipFile, and there is an encrypted entry. Setting the Encryption property on that ZipFile and then calling Save() on the ZipFile does not update the Encryption used for the entries in the archive. Neither is an exception thrown. Instead, what happens during the Save() is that all previously existing entries are copied through to the new zip archive, with whatever encryption and password that was used when originally creating the zip archive. Upon re-reading that archive, to extract entries, applications should use the original password or passwords, if any. Suppose an application reads a ZipFile, and there is an encrypted entry. Setting the Encryption property on that ZipFile and then adding new entries (via AddFile(), AddEntry(), etc) and then calling Save() on the ZipFile does not update the Encryption on any of the entries that had previously been in the ZipFile. The Encryption property applies only to the newly-added entries. This example creates a zip archive that uses encryption, and then extracts entries from the archive. When creating the zip archive, the ReadMe.txt file is zipped without using a password or encryption. The other files use encryption.


             // Create a zip archive with AES Encryption.
             using (ZipFile zip = new ZipFile())
             {
                 zip.AddFile("ReadMe.txt");
                 zip.Encryption= EncryptionAlgorithm.WinZipAes256;
                 zip.Password= "Top.Secret.No.Peeking!";
                 zip.AddFile("7440-N49th.png");
                 zip.AddFile("2008-Regional-Sales-Report.pdf");
                 zip.Save("EncryptedArchive.zip");
             }
            
             // Extract a zip archive that uses AES Encryption.
             // You do not need to specify the algorithm during extraction.
             using (ZipFile zip = ZipFile.Read("EncryptedArchive.zip"))
             {
                 zip.Password= "Top.Secret.No.Peeking!";
                 zip.ExtractAll("extractDirectory");
             }


             ' Create a zip that uses Encryption.
             Using zip As New ZipFile()
                 zip.Encryption= EncryptionAlgorithm.WinZipAes256
                 zip.Password= "Top.Secret.No.Peeking!"
                 zip.AddFile("ReadMe.txt")
                 zip.AddFile("7440-N49th.png")
                 zip.AddFile("2008-Regional-Sales-Report.pdf")
                 zip.Save("EncryptedArchive.zip")
             End Using
            
             ' Extract a zip archive that uses AES Encryption.
             ' You do not need to specify the algorithm during extraction.
             Using (zip as ZipFile = ZipFile.Read("EncryptedArchive.zip"))
                 zip.Password= "Top.Secret.No.Peeking!"
                 zip.ExtractAll("extractDirectory")
             End Using

ZipFile.Password ZipEntry.Encryption

A callback that allows the application to specify the compression level to use for entries subsequently added to the zip archive.

With this callback, the DotNetZip library allows the application to determine whether compression will be used, at the time of the Save. This may be useful if the application wants to favor speed over size, and wants to defer the decision until the time of Save. Typically applications set the property on the ZipFile or on each ZipEntry to determine the level of compression used. This is done at the time the entry is added to the ZipFile. Setting the property to Ionic.Zlib.CompressionLevel.None means no compression will be used. This callback allows the application to defer the decision on the CompressionLevel to use, until the time of the call to ZipFile.Save(). The callback is invoked once per ZipEntry, at the time the data for the entry is being written out as part of a Save() operation. The application can use whatever criteria it likes in determining the level to return. For example, an application may wish that no .mp3 files should be compressed, because they are already compressed and the extra compression is not worth the CPU time incurred, and so can return None for all .mp3 entries. The library determines whether compression will be attempted for an entry this way: If the entry is a zero length file, or a directory, no compression is used. Otherwise, if this callback is set, it is invoked and the CompressionLevel is set to the return value. If this callback has not been set, then the previously set value for CompressionLevel is used.

The maximum size of an output segment, when saving a split Zip file.

Set this to a non-zero value before calling or to specify that the ZipFile should be saved as a split archive, also sometimes called a spanned archive. Some also call them multi-file archives. A split zip archive is saved in a set of discrete filesystem files, rather than in a single file. This is handy when transmitting the archive in email or some other mechanism that has file size limits. The first file in a split archive will be named basename.z01, the second will be named basename.z02, and so on. The final file is named basename.zip. The value of this property determines the maximum size of a split segment when writing a split archive. According to the zip specification from PKWare, the minimum value is 65536, for a 64k segment size. For example, suppose you have a ZipFile that would save to a single file of 200k. If you set the MaxOutputSegmentSize to 65536 before calling Save(), you will get four distinct output files. On the other hand if you set this property to 256k, then you will get a single-file archive for that ZipFile. The size of each split output file will often but not always be exactly the maximum size set here. The zip specification requires that some data fields in a zip archive may not span a split boundary. An output segment may be not completely filled if necessary to avoid that problem. Also, obviously the final segment of the archive may be smaller than the maximum segment size. Segments will never be larger than the value set with this property. You can save a split Zip file only when saving to a regular filesystem file. It's not possible to save a split zip file as a self-extracting archive, nor is it possible to save a split zip file to a stream. When saving to a SFX or to a Stream, this property is ignored. About interoperability: Split or spanned zip files produced by DotNetZip can be read by WinZip or PKZip, and vice-versa. Segmented zip files may not be readable by other tools, if those other tools don't support zip spanning or splitting. When in doubt, test. I don't believe Windows Explorer can extract a split archive. This property has no effect when reading a split archive. You can read a split archive in the normal way with DotNetZip. When saving a zip file, if you want a regular zip file rather than a split zip file, don't set this property, or set it to Zero. If you read a split archive, with and then subsequently call ZipFile.Save(), unless you set this property before calling Save(), you will get a normal, single-file archive.

Returns the number of segments used in the most recent Save() operation.

This is normally zero, unless you have set the property. If you have set , and then you save a file, after the call to Save() completes, you can read this value to learn the number of segments that were created. If you call Save("Archive.zip"), and it creates 5 segments, then you will have filesystem files named Archive.z01, Archive.z02, Archive.z03, Archive.z04, and Archive.zip, and the value of this property will be 5.

The size threshold for an entry, above which a parallel deflate is used.

DotNetZip will use multiple threads to compress any ZipEntry, if the entry is larger than the given size. Zero means "always use parallel deflate", while -1 means "never use parallel deflate". The default value for this property is 512k. Aside from the special values of 0 and 1, the minimum value is 65536. If the entry size cannot be known before compression, as with a read-forward stream, then Parallel deflate will never be performed, unless the value of this property is zero. A parallel deflate operations will speed up the compression of large files, on computers with multiple CPUs or multiple CPU cores. For files above 1mb, on a dual core or dual-cpu (2p) machine, the time required to compress the file can be 70% of the single-threaded deflate. For very large files on 4p machines the compression can be done in 30% of the normal time. The downside is that parallel deflate consumes extra memory during the deflate, and the deflation is not as effective. Parallel deflate tends to not be as effective as single-threaded deflate because the original data stream is split into multiple independent buffers, each of which is compressed in parallel. But because they are treated independently, there is no opportunity to share compression dictionaries. For that reason, a deflated stream may be slightly larger when compressed using parallel deflate, as compared to a traditional single-threaded deflate. Sometimes the increase over the normal deflate is as much as 5% of the total compressed size. For larger files it can be as small as 0.1%. Multi-threaded compression does not give as much an advantage when using Encryption. This is primarily because encryption tends to slow down the entire pipeline. Also, multi-threaded compression gives less of an advantage when using lower compression levels, for example . You may have to perform some tests to determine the best approach for your situation.

Returns the version number on the DotNetZip assembly.

This property is exposed as a convenience. Callers could also get the version value by retrieving GetName().Version on the System.Reflection.Assembly object pointing to the DotNetZip assembly. But sometimes it is not clear which assembly is being loaded. This property makes it clear. This static property is primarily useful for diagnostic purposes.

This is an integer indexer into the Zip archive.

This property is read-only. Internally, the ZipEntry instances that belong to the ZipFile are stored in a Dictionary. When you use this indexer the first time, it creates a read-only List<ZipEntry> from the Dictionary.Values Collection. If at any time you modify the set of entries in the ZipFile, either by adding an entry, removing an entry, or renaming an entry, a new List will be created, and the numeric indexes for the remaining entries may be different. This means you cannot rename any ZipEntry from inside an enumeration of the zip file. The index value. The ZipEntry within the Zip archive at the specified index. If the entry does not exist in the archive, this indexer throws.

This is a name-based indexer into the Zip archive.

This property is read-only. The property on the ZipFile determines whether retrieval via this indexer is done via case-sensitive comparisons. By default, retrieval is not case sensitive. This makes sense on Windows, in which filesystems are not case sensitive. Regardless of case-sensitivity, it is not always the case that this[value].FileName == value. In other words, the FileName property of the ZipEntry retrieved with this indexer, may or may not be equal to the index value. This is because DotNetZip performs a normalization of filenames passed to this indexer, before attempting to retrieve the item. That normalization includes: removal of a volume letter and colon, swapping backward slashes for forward slashes. So, zip["dir1\\entry1.txt"].FileName == "dir1/entry.txt". Directory entries in the zip file may be retrieved via this indexer only with names that have a trailing slash. DotNetZip automatically appends a trailing slash to the names of any directory entries added to a zip. This example extracts only the entries in a zip file that are .txt files.


             using (ZipFile zip = ZipFile.Read("PackedDocuments.zip"))
             {
               foreach (string s1 in zip.EntryFilenames)
               {
                 if (s1.EndsWith(".txt"))
                   zip[s1].Extract("textfiles");
               }
             }


               Using zip As ZipFile = ZipFile.Read("PackedDocuments.zip")
                   Dim s1 As String
                   For Each s1 In zip.EntryFilenames
                       If s1.EndsWith(".txt") Then
                           zip(s1).Extract("textfiles")
                       End If
                   Next
               End Using

Thrown if the caller attempts to assign a non-null value to the indexer. The name of the file, including any directory path, to retrieve from the zip. The filename match is not case-sensitive by default; you can use the property to change this behavior. The pathname can use forward-slashes or backward slashes. The ZipEntry within the Zip archive, given by the specified filename. If the named entry does not exist in the archive, this indexer returns null (Nothing in VB).

The list of filenames for the entries contained within the zip archive.

According to the ZIP specification, the names of the entries use forward slashes in pathnames. If you are scanning through the list, you may have to swap forward slashes for backslashes. This example shows one way to test if a filename is already contained within a zip archive.


             String zipFileToRead= "PackedDocuments.zip";
             string candidate = "DatedMaterial.xps";
             using (ZipFile zip = new ZipFile(zipFileToRead))
             {
               if (zip.EntryFilenames.Contains(candidate))
                 Console.WriteLine("The file '{0}' exists in the zip archive '{1}'",
                                   candidate,
                                   zipFileName);
               else
                 Console.WriteLine("The file, '{0}', does not exist in the zip archive '{1}'",
                                   candidate,
                                   zipFileName);
               Console.WriteLine();
             }


               Dim zipFileToRead As String = "PackedDocuments.zip"
               Dim candidate As String = "DatedMaterial.xps"
               Using zip As ZipFile.Read(ZipFileToRead)
                   If zip.EntryFilenames.Contains(candidate) Then
                       Console.WriteLine("The file '{0}' exists in the zip archive '{1}'", _
                                   candidate, _
                                   zipFileName)
                   Else
                     Console.WriteLine("The file, '{0}', does not exist in the zip archive '{1}'", _
                                   candidate, _
                                   zipFileName)
                   End If
                   Console.WriteLine
               End Using

The list of strings for the filenames contained within the Zip archive.

Returns the readonly collection of entries in the Zip archive.

If there are no entries in the current ZipFile, the value returned is a non-null zero-element collection. If there are entries in the zip file, the elements are returned in no particular order. This is the implied enumerator on the ZipFile class. If you use a ZipFile instance in a context that expects an enumerator, you will get this collection.

Returns a readonly collection of entries in the Zip archive, sorted by FileName.

If there are no entries in the current ZipFile, the value returned is a non-null zero-element collection. If there are entries in the zip file, the elements are returned sorted by the name of the entry. This example fills a Windows Forms ListView with the entries in a zip file.


             using (ZipFile zip = ZipFile.Read(zipFile))
             {
                 foreach (ZipEntry entry in zip.EntriesSorted)
                 {
                     ListViewItem item = new ListViewItem(n.ToString());
                     n++;
                     string[] subitems = new string[] {
                         entry.FileName.Replace("/","\\"),
                         entry.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
                         entry.UncompressedSize.ToString(),
                         String.Format("{0,5:F0}%", entry.CompressionRatio),
                         entry.CompressedSize.ToString(),
                         (entry.UsesEncryption) ? "Y" : "N",
                         String.Format("{0:X8}", entry.Crc)};
            
                     foreach (String s in subitems)
                     {
                         ListViewItem.ListViewSubItem subitem = new ListViewItem.ListViewSubItem();
                         subitem.Text = s;
                         item.SubItems.Add(subitem);
                     }
            
                     this.listView1.Items.Add(item);
                 }
             }

Returns the number of entries in the Zip archive.

Provides a human-readable string with information about the ZipFile.

The information string contains 10 lines or so, about each ZipEntry, describing whether encryption is in use, the compressed and uncompressed length of the entry, the offset of the entry, and so on. As a result the information string can be very long for zip files that contain many entries. This information is mostly useful for diagnostic purposes.

An event handler invoked when a Save() starts, before and after each entry has been written to the archive, when a Save() completes, and during other Save events.

Depending on the particular event, different properties on the parameter are set. The following table summarizes the available EventTypes and the conditions under which this event handler is invoked with a SaveProgressEventArgs with the given EventType. value of EntryType Meaning and conditions ZipProgressEventType.Saving_Started Fired when ZipFile.Save() begins. ZipProgressEventType.Saving_BeforeSaveEntry Fired within ZipFile.Save(), just before writing data for each particular entry. ZipProgressEventType.Saving_AfterSaveEntry Fired within ZipFile.Save(), just after having finished writing data for each particular entry. ZipProgressEventType.Saving_Completed Fired when ZipFile.Save() has completed. ZipProgressEventType.Saving_AfterSaveTempArchive Fired after the temporary file has been created. This happens only when saving to a disk file. This event will not be invoked when saving to a stream. ZipProgressEventType.Saving_BeforeRenameTempArchive Fired just before renaming the temporary file to the permanent location. This happens only when saving to a disk file. This event will not be invoked when saving to a stream. ZipProgressEventType.Saving_AfterRenameTempArchive Fired just after renaming the temporary file to the permanent location. This happens only when saving to a disk file. This event will not be invoked when saving to a stream. ZipProgressEventType.Saving_AfterCompileSelfExtractor Fired after a self-extracting archive has finished compiling. This EventType is used only within SaveSelfExtractor(). ZipProgressEventType.Saving_BytesRead Set during the save of a particular entry, to update progress of the Save(). When this EventType is set, the BytesTransferred is the number of bytes that have been read from the source stream. The TotalBytesToTransfer is the number of bytes in the uncompressed file. This example uses an anonymous method to handle the SaveProgress event, by updating a progress bar.


             progressBar1.Value = 0;
             progressBar1.Max = listbox1.Items.Count;
             using (ZipFile zip = new ZipFile())
             {
                // listbox1 contains a list of filenames
                zip.AddFiles(listbox1.Items);
            
                // do the progress bar:
                zip.SaveProgress += (sender, e) => {
                   if (e.EventType == ZipProgressEventType.Saving_BeforeWriteEntry) {
                      progressBar1.PerformStep();
                   }
                };
            
                zip.Save(fs);
             }

This example uses a named method as the SaveProgress event handler, to update the user, in a console-based application.


             static bool justHadByteUpdate= false;
             public static void SaveProgress(object sender, SaveProgressEventArgs e)
             {
                 if (e.EventType == ZipProgressEventType.Saving_Started)
                     Console.WriteLine("Saving: {0}", e.ArchiveName);
            
                 else if (e.EventType == ZipProgressEventType.Saving_Completed)
                 {
                     justHadByteUpdate= false;
                     Console.WriteLine();
                     Console.WriteLine("Done: {0}", e.ArchiveName);
                 }
            
                 else if (e.EventType == ZipProgressEventType.Saving_BeforeWriteEntry)
                 {
                     if (justHadByteUpdate)
                         Console.WriteLine();
                     Console.WriteLine("  Writing: {0} ({1}/{2})",
                                       e.CurrentEntry.FileName, e.EntriesSaved, e.EntriesTotal);
                     justHadByteUpdate= false;
                 }
            
                 else if (e.EventType == ZipProgressEventType.Saving_EntryBytesRead)
                 {
                     if (justHadByteUpdate)
                         Console.SetCursorPosition(0, Console.CursorTop);
                      Console.Write("     {0}/{1} ({2:N0}%)", e.BytesTransferred, e.TotalBytesToTransfer,
                                   e.BytesTransferred / (0.01 * e.TotalBytesToTransfer ));
                     justHadByteUpdate= true;
                 }
             }
            
             public static ZipUp(string targetZip, string directory)
             {
               using (var zip = new ZipFile()) {
                 zip.SaveProgress += SaveProgress;
                 zip.AddDirectory(directory);
                 zip.Save(targetZip);
               }
             }


             Public Sub ZipUp(ByVal targetZip As String, ByVal directory As String)
                 Using zip As ZipFile = New ZipFile
                     AddHandler zip.SaveProgress, AddressOf MySaveProgress
                     zip.AddDirectory(directory)
                     zip.Save(targetZip)
                 End Using
             End Sub
            
             Private Shared justHadByteUpdate As Boolean = False
            
             Public Shared Sub MySaveProgress(ByVal sender As Object, ByVal e As SaveProgressEventArgs)
                 If (e.EventType Is ZipProgressEventType.Saving_Started) Then
                     Console.WriteLine("Saving: {0}", e.ArchiveName)
            
                 ElseIf (e.EventType Is ZipProgressEventType.Saving_Completed) Then
                     justHadByteUpdate = False
                     Console.WriteLine
                     Console.WriteLine("Done: {0}", e.ArchiveName)
            
                 ElseIf (e.EventType Is ZipProgressEventType.Saving_BeforeWriteEntry) Then
                     If justHadByteUpdate Then
                         Console.WriteLine
                     End If
                     Console.WriteLine("  Writing: {0} ({1}/{2})", e.CurrentEntry.FileName, e.EntriesSaved, e.EntriesTotal)
                     justHadByteUpdate = False
            
                 ElseIf (e.EventType Is ZipProgressEventType.Saving_EntryBytesRead) Then
                     If justHadByteUpdate Then
                         Console.SetCursorPosition(0, Console.CursorTop)
                     End If
                     Console.Write("     {0}/{1} ({2:N0}%)", e.BytesTransferred, _
                                   e.TotalBytesToTransfer, _
                                   (CDbl(e.BytesTransferred) / (0.01 * e.TotalBytesToTransfer)))
                     justHadByteUpdate = True
                 End If
             End Sub

This is a more complete example of using the SaveProgress events in a Windows Forms application, with a Thread object.


             delegate void SaveEntryProgress(SaveProgressEventArgs e);
             delegate void ButtonClick(object sender, EventArgs e);
            
             public class WorkerOptions
             {
                 public string ZipName;
                 public string Folder;
                 public string Encoding;
                 public string Comment;
                 public int ZipFlavor;
                 public Zip64Option Zip64;
             }
            
             private int _progress2MaxFactor;
             private bool _saveCanceled;
             private long _totalBytesBeforeCompress;
             private long _totalBytesAfterCompress;
             private Thread _workerThread;
            
            
             private void btnZipup_Click(object sender, EventArgs e)
             {
                 KickoffZipup();
             }
            
             private void btnCancel_Click(object sender, EventArgs e)
             {
                 if (this.lblStatus.InvokeRequired)
                 {
                     this.lblStatus.Invoke(new ButtonClick(this.btnCancel_Click), new object[] { sender, e });
                 }
                 else
                 {
                     _saveCanceled = true;
                     lblStatus.Text = "Canceled...";
                     ResetState();
                 }
             }
            
             private void KickoffZipup()
             {
                 _folderName = tbDirName.Text;
            
                 if (_folderName == null || _folderName == "") return;
                 if (this.tbZipName.Text == null || this.tbZipName.Text == "") return;
            
                 // check for existence of the zip file:
                 if (System.IO.File.Exists(this.tbZipName.Text))
                 {
                     var dlgResult = MessageBox.Show(String.Format("The file you have specified ({0}) already exists." +
                                                                   "  Do you want to overwrite this file?", this.tbZipName.Text),
                                                     "Confirmation is Required", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
                     if (dlgResult != DialogResult.Yes) return;
                     System.IO.File.Delete(this.tbZipName.Text);
                 }
            
                  _saveCanceled = false;
                 _nFilesCompleted = 0;
                 _totalBytesAfterCompress = 0;
                 _totalBytesBeforeCompress = 0;
                 this.btnOk.Enabled = false;
                 this.btnOk.Text = "Zipping...";
                 this.btnCancel.Enabled = true;
                 lblStatus.Text = "Zipping...";
            
                 var options = new WorkerOptions
                 {
                     ZipName = this.tbZipName.Text,
                     Folder = _folderName,
                     Encoding = "ibm437"
                 };
            
                 if (this.comboBox1.SelectedIndex != 0)
                 {
                     options.Encoding = this.comboBox1.SelectedItem.ToString();
                 }
            
                 if (this.radioFlavorSfxCmd.Checked)
                     options.ZipFlavor = 2;
                 else if (this.radioFlavorSfxGui.Checked)
                     options.ZipFlavor = 1;
                 else options.ZipFlavor = 0;
            
                 if (this.radioZip64AsNecessary.Checked)
                     options.Zip64 = Zip64Option.AsNecessary;
                 else if (this.radioZip64Always.Checked)
                     options.Zip64 = Zip64Option.Always;
                 else options.Zip64 = Zip64Option.Never;
            
                 options.Comment = String.Format("Encoding:{0} || Flavor:{1} || ZIP64:{2}\r\nCreated at {3} || {4}\r\n",
                             options.Encoding,
                             FlavorToString(options.ZipFlavor),
                             options.Zip64.ToString(),
                             System.DateTime.Now.ToString("yyyy-MMM-dd HH:mm:ss"),
                             this.Text);
            
                 if (this.tbComment.Text != TB_COMMENT_NOTE)
                     options.Comment += this.tbComment.Text;
            
                 _workerThread = new Thread(this.DoSave);
                 _workerThread.Name = "Zip Saver thread";
                 _workerThread.Start(options);
                 this.Cursor = Cursors.WaitCursor;
              }
            
            
             private void DoSave(Object p)
             {
                 WorkerOptions options = p as WorkerOptions;
                 try
                 {
                     using (var zip1 = new ZipFile())
                     {
                         zip1.ProvisionalAlternateEncoding = System.Text.Encoding.GetEncoding(options.Encoding);
                         zip1.Comment = options.Comment;
                         zip1.AddDirectory(options.Folder);
                         _entriesToZip = zip1.EntryFileNames.Count;
                         SetProgressBars();
                         zip1.SaveProgress += this.zip1_SaveProgress;
            
                         zip1.UseZip64WhenSaving = options.Zip64;
            
                         if (options.ZipFlavor == 1)
                             zip1.SaveSelfExtractor(options.ZipName, SelfExtractorFlavor.WinFormsApplication);
                         else if (options.ZipFlavor == 2)
                             zip1.SaveSelfExtractor(options.ZipName, SelfExtractorFlavor.ConsoleApplication);
                         else
                             zip1.Save(options.ZipName);
                     }
                 }
                 catch (System.Exception exc1)
                 {
                     MessageBox.Show(String.Format("Exception while zipping: {0}", exc1.Message));
                     btnCancel_Click(null, null);
                 }
             }
            
            
            
             void zip1_SaveProgress(object sender, SaveProgressEventArgs e)
             {
                 switch (e.EventType)
                 {
                     case ZipProgressEventType.Saving_AfterWriteEntry:
                         StepArchiveProgress(e);
                         break;
                     case ZipProgressEventType.Saving_EntryBytesRead:
                         StepEntryProgress(e);
                         break;
                     case ZipProgressEventType.Saving_Completed:
                         SaveCompleted();
                         break;
                     case ZipProgressEventType.Saving_AfterSaveTempArchive:
                         // this event only occurs when saving an SFX file
                         TempArchiveSaved();
                         break;
                 }
                 if (_saveCanceled)
                     e.Cancel = true;
             }
            
            
            
             private void StepArchiveProgress(SaveProgressEventArgs e)
             {
                 if (this.progressBar1.InvokeRequired)
                 {
                     this.progressBar1.Invoke(new SaveEntryProgress(this.StepArchiveProgress), new object[] { e });
                 }
                 else
                 {
                     if (!_saveCanceled)
                     {
                         _nFilesCompleted++;
                         this.progressBar1.PerformStep();
                         _totalBytesAfterCompress += e.CurrentEntry.CompressedSize;
                         _totalBytesBeforeCompress += e.CurrentEntry.UncompressedSize;
            
                         // reset the progress bar for the entry:
                         this.progressBar2.Value = this.progressBar2.Maximum = 1;
            
                         this.Update();
                     }
                 }
             }
            
            
             private void StepEntryProgress(SaveProgressEventArgs e)
             {
                 if (this.progressBar2.InvokeRequired)
                 {
                     this.progressBar2.Invoke(new SaveEntryProgress(this.StepEntryProgress), new object[] { e });
                 }
                 else
                 {
                     if (!_saveCanceled)
                     {
                         if (this.progressBar2.Maximum == 1)
                         {
                             // reset
                             Int64 max = e.TotalBytesToTransfer;
                             _progress2MaxFactor = 0;
                             while (max > System.Int32.MaxValue)
                             {
                                 max /= 2;
                                 _progress2MaxFactor++;
                             }
                             this.progressBar2.Maximum = (int)max;
                             lblStatus.Text = String.Format("{0} of {1} files...({2})",
                                 _nFilesCompleted + 1, _entriesToZip, e.CurrentEntry.FileName);
                         }
            
                          int xferred = e.BytesTransferred >> _progress2MaxFactor;
            
                          this.progressBar2.Value = (xferred >= this.progressBar2.Maximum)
                             ? this.progressBar2.Maximum
                             : xferred;
            
                          this.Update();
                     }
                 }
             }
            
             private void SaveCompleted()
             {
                 if (this.lblStatus.InvokeRequired)
                 {
                     this.lblStatus.Invoke(new MethodInvoker(this.SaveCompleted));
                 }
                 else
                 {
                     lblStatus.Text = String.Format("Done, Compressed {0} files, {1:N0}% of original.",
                         _nFilesCompleted, (100.00 * _totalBytesAfterCompress) / _totalBytesBeforeCompress);
                      ResetState();
                 }
             }
            
             private void ResetState()
             {
                 this.btnCancel.Enabled = false;
                 this.btnOk.Enabled = true;
                 this.btnOk.Text = "Zip it!";
                 this.progressBar1.Value = 0;
                 this.progressBar2.Value = 0;
                 this.Cursor = Cursors.Default;
                 if (!_workerThread.IsAlive)
                     _workerThread.Join();
             }

An event handler invoked before, during, and after the reading of a zip archive.

Depending on the particular event being signaled, different properties on the parameter are set. The following table summarizes the available EventTypes and the conditions under which this event handler is invoked with a ReadProgressEventArgs with the given EventType. value of EntryType Meaning and conditions ZipProgressEventType.Reading_Started Fired just as ZipFile.Read() begins. Meaningful properties: ArchiveName. ZipProgressEventType.Reading_Completed Fired when ZipFile.Read() has completed. Meaningful properties: ArchiveName. ZipProgressEventType.Reading_ArchiveBytesRead Fired while reading, updates the number of bytes read for the entire archive. Meaningful properties: ArchiveName, CurrentEntry, BytesTransferred, TotalBytesToTransfer. ZipProgressEventType.Reading_BeforeReadEntry Indicates an entry is about to be read from the archive. Meaningful properties: ArchiveName, EntriesTotal. ZipProgressEventType.Reading_AfterReadEntry Indicates an entry has just been read from the archive. Meaningful properties: ArchiveName, EntriesTotal, CurrentEntry.

An event handler invoked before, during, and after extraction of entries in the zip archive.

Depending on the particular event, different properties on the parameter are set. The following table summarizes the available EventTypes and the conditions under which this event handler is invoked with a ExtractProgressEventArgs with the given EventType. value of EntryType Meaning and conditions ZipProgressEventType.Extracting_BeforeExtractAll Set when ExtractAll() begins. The ArchiveName, Overwrite, and ExtractLocation properties are meaningful. ZipProgressEventType.Extracting_AfterExtractAll Set when ExtractAll() has completed. The ArchiveName, Overwrite, and ExtractLocation properties are meaningful. ZipProgressEventType.Extracting_BeforeExtractEntry Set when an Extract() on an entry in the ZipFile has begun. Properties that are meaningful: ArchiveName, EntriesTotal, CurrentEntry, Overwrite, ExtractLocation, EntriesExtracted. ZipProgressEventType.Extracting_AfterExtractEntry Set when an Extract() on an entry in the ZipFile has completed. Properties that are meaningful: ArchiveName, EntriesTotal, CurrentEntry, Overwrite, ExtractLocation, EntriesExtracted. ZipProgressEventType.Extracting_EntryBytesWritten Set within a call to Extract() on an entry in the ZipFile, as data is extracted for the entry. Properties that are meaningful: ArchiveName, CurrentEntry, BytesTransferred, TotalBytesToTransfer. ZipProgressEventType.Extracting_ExtractEntryWouldOverwrite Set within a call to Extract() on an entry in the ZipFile, when the extraction would overwrite an existing file. This event type is used only when ExtractExistingFileAction on the ZipFile or ZipEntry is set to InvokeExtractProgressEvent.


             private static bool justHadByteUpdate = false;
             public static void ExtractProgress(object sender, ExtractProgressEventArgs e)
             {
               if(e.EventType == ZipProgressEventType.Extracting_EntryBytesWritten)
               {
                 if (justHadByteUpdate)
                   Console.SetCursorPosition(0, Console.CursorTop);
            
                 Console.Write("   {0}/{1} ({2:N0}%)", e.BytesTransferred, e.TotalBytesToTransfer,
                               e.BytesTransferred / (0.01 * e.TotalBytesToTransfer ));
                 justHadByteUpdate = true;
               }
               else if(e.EventType == ZipProgressEventType.Extracting_BeforeExtractEntry)
               {
                 if (justHadByteUpdate)
                   Console.WriteLine();
                 Console.WriteLine("Extracting: {0}", e.CurrentEntry.FileName);
                 justHadByteUpdate= false;
               }
             }
            
             public static ExtractZip(string zipToExtract, string directory)
             {
               string TargetDirectory= "extract";
               using (var zip = ZipFile.Read(zipToExtract)) {
                 zip.ExtractProgress += ExtractProgress;
                 foreach (var e in zip1)
                 {
                   e.Extract(TargetDirectory, true);
                 }
               }
             }


             Public Shared Sub Main(ByVal args As String())
                 Dim ZipToUnpack As String = "C1P3SML.zip"
                 Dim TargetDir As String = "ExtractTest_Extract"
                 Console.WriteLine("Extracting file {0} to {1}", ZipToUnpack, TargetDir)
                 Using zip1 As ZipFile = ZipFile.Read(ZipToUnpack)
                     AddHandler zip1.ExtractProgress, AddressOf MyExtractProgress
                     Dim e As ZipEntry
                     For Each e In zip1
                         e.Extract(TargetDir, True)
                     Next
                 End Using
             End Sub
            
             Private Shared justHadByteUpdate As Boolean = False
            
             Public Shared Sub MyExtractProgress(ByVal sender As Object, ByVal e As ExtractProgressEventArgs)
                 If (e.EventType = ZipProgressEventType.Extracting_EntryBytesWritten) Then
                     If ExtractTest.justHadByteUpdate Then
                         Console.SetCursorPosition(0, Console.CursorTop)
                     End If
                     Console.Write("   {0}/{1} ({2:N0}%)", e.BytesTransferred, e.TotalBytesToTransfer, (CDbl(e.BytesTransferred) / (0.01 * e.TotalBytesToTransfer)))
                     ExtractTest.justHadByteUpdate = True
                 ElseIf (e.EventType = ZipProgressEventType.Extracting_BeforeExtractEntry) Then
                     If ExtractTest.justHadByteUpdate Then
                         Console.WriteLine
                     End If
                     Console.WriteLine("Extracting: {0}", e.CurrentEntry.FileName)
                     ExtractTest.justHadByteUpdate = False
                 End If
             End Sub

An event handler invoked before, during, and after Adding entries to a zip archive.

Adding a large number of entries to a zip file can take a long time. For example, when calling on a directory that contains 50,000 files, it could take 3 minutes or so. This event handler allws an application to track the progress of the Add operation.


            
             int _numEntriesToAdd= 0;
             int _numEntriesAdded= 0;
             void AddProgressHandler(object sender, AddProgressEventArgs e)
             {
                 switch (e.EventType)
                 {
                     case ZipProgressEventType.Adding_Started:
                         Console.WriteLine("Adding files to the zip...");
                         break;
                     case ZipProgressEventType.Adding_AfterAddEntry:
                         _numEntriesAdded++;
                         Console.WriteLine(String.Format("Adding file {0}/{1} :: {2}",
                                                  _numEntriesAdded, _numEntriesToAdd, e.CurrentEntry.FileName));
                         break;
                     case ZipProgressEventType.Adding_Completed:
                         Console.WriteLine("Added all files");
                         break;
                 }
             }
            
             void CreateTheZip()
             {
                 using (ZipFile zip = new ZipFile())
                 {
                     zip.AddProgress += AddProgressHandler;
                     zip.AddDirectory(System.IO.Path.GetFileName(DirToZip));
                     zip.Save(ZipFileToCreate);
                 }
             }


            
             Private Sub AddProgressHandler(ByVal sender As Object, ByVal e As AddProgressEventArgs)
                 Select Case e.EventType
                     Case ZipProgressEventType.Adding_Started
                         Console.WriteLine("Adding files to the zip...")
                         Exit Select
                     Case ZipProgressEventType.Adding_AfterAddEntry
                         Console.WriteLine(String.Format("Adding file {0}", e.CurrentEntry.FileName))
                         Exit Select
                     Case ZipProgressEventType.Adding_Completed
                         Console.WriteLine("Added all files")
                         Exit Select
                 End Select
             End Sub
            
             Sub CreateTheZip()
                 Using zip as ZipFile = New ZipFile
                     AddHandler zip.AddProgress, AddressOf AddProgressHandler
                     zip.AddDirectory(System.IO.Path.GetFileName(DirToZip))
                     zip.Save(ZipFileToCreate);
                 End Using
             End Sub

An event that is raised when an error occurs during open or read of files while saving a zip archive.

Errors can occur as a file is being saved to the zip archive. For example, the File.Open may fail, or a File.Read may fail, because of lock conflicts or other reasons. If you add a handler to this event, you can handle such errors in your own code. If you don't add a handler, the library will throw an exception if it encounters an I/O error during a call to Save(). Setting a handler implicitly sets to ZipErrorAction.InvokeErrorEvent. The handler you add applies to all items that are subsequently added to the ZipFile instance. If you set this property after you have added items to the ZipFile, but before you have called Save(), errors that occur while saving those items will not cause the error handler to be invoked. If you want to handle any errors that occur with any entry in the zip file using the same error handler, then add your error handler once, before adding any entries to the zip archive. In the error handler method, you need to set the property on the ZipErrorEventArgs.CurrentEntry. This communicates back to DotNetZip what you would like to do with this particular error. Within an error handler, if you set the ZipEntry.ZipErrorAction property on the ZipEntry to ZipErrorAction.InvokeErrorEvent or if you don't set it at all, the library will throw the exception. (It is the same as if you had set the ZipEntry.ZipErrorAction property on the ZipEntry to ZipErrorAction.Throw.) If you set the ZipErrorEventArgs.Cancel to true, the entire Save() will be canceled. This example shows how to use an event handler to handle errors during save of the zip file.


            
             public static void MyZipError(object sender, ZipErrorEventArgs e)
             {
                 Console.WriteLine("Error saving {0}...", e.FileName);
                 Console.WriteLine("   Exception: {0}", e.exception);
                 ZipEntry entry = e.CurrentEntry;
                 string response = null;
                 // Ask the user whether he wants to skip this error or not
                 do
                 {
                     Console.Write("Retry, Skip, Throw, or Cancel ? (R/S/T/C) ");
                     response = Console.ReadLine();
                     Console.WriteLine();
            
                 } while (response != null &&
                          response[0]!='S' && response[0]!='s' &&
                          response[0]!='R' && response[0]!='r' &&
                          response[0]!='T' && response[0]!='t' &&
                          response[0]!='C' && response[0]!='c');
            
                 e.Cancel = (response[0]=='C' || response[0]=='c');
            
                 if (response[0]=='S' || response[0]=='s')
                     entry.ZipErrorAction = ZipErrorAction.Skip;
                 else if (response[0]=='R' || response[0]=='r')
                     entry.ZipErrorAction = ZipErrorAction.Retry;
                 else if (response[0]=='T' || response[0]=='t')
                     entry.ZipErrorAction = ZipErrorAction.Throw;
             }
            
             public void SaveTheFile()
             {
               string directoryToZip = "fodder";
               string directoryInArchive = "files";
               string zipFileToCreate = "Archive.zip";
               using (var zip = new ZipFile())
               {
                 // set the event handler before adding any entries
                 zip.ZipError += MyZipError;
                 zip.AddDirectory(directoryToZip, directoryInArchive);
                 zip.Save(zipFileToCreate);
               }
             }


             Private Sub MyZipError(ByVal sender As Object, ByVal e As Ionic.Zip.ZipErrorEventArgs)
                 ' At this point, the application could prompt the user for an action to take.
                 ' But in this case, this application will simply automatically skip the file, in case of error.
                 Console.WriteLine("Zip Error,  entry {0}", e.CurrentEntry.FileName)
                 Console.WriteLine("   Exception: {0}", e.exception)
                 ' set the desired ZipErrorAction on the CurrentEntry to communicate that to DotNetZip
                 e.CurrentEntry.ZipErrorAction = Zip.ZipErrorAction.Skip
             End Sub
            
             Public Sub SaveTheFile()
                 Dim directoryToZip As String = "fodder"
                 Dim directoryInArchive As String = "files"
                 Dim zipFileToCreate as String = "Archive.zip"
                 Using zipArchive As ZipFile = New ZipFile
                     ' set the event handler before adding any entries
                     AddHandler zipArchive.ZipError, AddressOf MyZipError
                     zipArchive.AddDirectory(directoryToZip, directoryInArchive)
                     zipArchive.Save(zipFileToCreate)
                 End Using
             End Sub

Options for using ZIP64 extensions when saving zip archives.

Designed many years ago, the original zip specification from PKWARE allowed for 32-bit quantities for the compressed and uncompressed sizes of zip entries, as well as a 32-bit quantity for specifying the length of the zip archive itself, and a maximum of 65535 entries. These limits are now regularly exceeded in many backup and archival scenarios. Recently, PKWare added extensions to the original zip spec, called "ZIP64 extensions", to raise those limitations. This property governs whether DotNetZip will use those extensions when writing zip archives. The use of these extensions is optional and explicit in DotNetZip because, despite the status of ZIP64 as a bona fide standard, many other zip tools and libraries do not support ZIP64, and therefore a zip file with ZIP64 extensions may be unreadable by some of those other tools. Set this property to to always use ZIP64 extensions when saving, regardless of whether your zip archive needs it. Suppose you add 5 files, each under 100k, to a ZipFile. If you specify Always for this flag, you will get a ZIP64 archive, though the archive does not need to use ZIP64 because none of the original zip limits had been exceeded. Set this property to to tell the DotNetZip library to never use ZIP64 extensions. This is useful for maximum compatibility and interoperability, at the expense of the capability of handling large files or large archives. NB: Windows Explorer in Windows XP and Windows Vista cannot currently extract files from a zip64 archive, so if you want to guarantee that a zip archive produced by this library will work in Windows Explorer, use Never. If you set this property to , and your application creates a zip that would exceed one of the Zip limits, the library will throw an exception while saving the zip file. Set this property to to tell the DotNetZip library to use the ZIP64 extensions when required by the entry. After the file is compressed, the original and compressed sizes are checked, and if they exceed the limits described above, then zip64 can be used. That is the general idea, but there is an additional wrinkle when saving to a non-seekable device, like the ASP.NET Response.OutputStream, or Console.Out. When using non-seekable streams for output, the entry header - which indicates whether zip64 is in use - is emitted before it is known if zip64 is necessary. It is only after all entries have been saved that it can be known if ZIP64 will be required. On seekable output streams, after saving all entries, the library can seek backward and re-emit the zip file header to be consistent with the actual ZIP64 requirement. But using a non-seekable output stream, the library cannot seek backward, so the header can never be changed. In other words, the archive's use of ZIP64 extensions is not alterable after the header is emitted. Therefore, when saving to non-seekable streams, using is the same as using : it will always produce a zip archive that uses ZIP64 extensions.

The default behavior, which is "Never". (For COM clients, this is a 0 (zero).)

Do not use ZIP64 extensions when writing zip archives. (For COM clients, this is a 0 (zero).)

Use ZIP64 extensions when writing zip archives, as necessary. For example, when a single entry exceeds 0xFFFFFFFF in size, or when the archive as a whole exceeds 0xFFFFFFFF in size, or when there are more than 65535 entries in an archive. (For COM clients, this is a 1.)

Always use ZIP64 extensions when writing zip archives, even when unnecessary. (For COM clients, this is a 2.)

Collects general purpose utility methods.

private null constructor

Utility routine for transforming path names from filesystem format (on Windows that means backslashes) to a format suitable for use within zipfiles. This means trimming the volume letter and colon (if any) And swapping backslashes for forward slashes.

source path. transformed path

Finds a signature in the zip stream. This is useful for finding the end of a zip entry, for example, or the beginning of the next ZipEntry.

Scans through 64k at a time. If the method fails to find the requested signature, the stream Position after completion of this method is unchanged. If the method succeeds in finding the requested signature, the stream position after completion is direct AFTER the signature found in the stream. The stream to search The 4-byte signature to find The number of bytes read

Create a pseudo-random filename, suitable for use as a temporary file, and open it.

The System.IO.Path.GetRandomFileName() method is not available on the Compact Framework, so this library provides its own substitute on NETCF. produces a filename of the form DotNetZip-xxxxxxxx.tmp, where xxxxxxxx is replaced by randomly chosen characters, and creates that file.

Workitem 7889: handle ERROR_LOCK_VIOLATION during read

This could be gracefully handled with an extension attribute, but This assembly is built for .NET 2.0, so I cannot use them.

A Stream wrapper, used for bookkeeping on input or output streams. In some cases, it is not possible to get the Position of a stream, let's say, on a write-only output stream like ASP.NET's Response.Output, or on a different write-only stream provided as the destination for the zip by the application. In this case, we can use this counting stream to count the bytes read or written.

The constructor.

The underlying stream

This class exposes a set of COM-accessible wrappers for static methods available on the ZipFile class. You don't need this class unless you are using DotNetZip from a COM environment.

A wrapper for ZipFile.IsZipFile(string)

The filename to of the zip file to check. true if the file contains a valid zip file.

A wrapper for ZipFile.IsZipFile(string, bool)

We cannot use "overloaded" Method names in COM interop. So, here, we use a unique name. The filename to of the zip file to check. true if the file contains a valid zip file.

A wrapper for ZipFile.CheckZip(string)

The filename to of the zip file to check. true if the named zip file checks OK. Otherwise, false.

A wrapper for ZipFile.FixZipDirectory(string)

The filename to of the zip file to fix.

A wrapper for ZipFile.LibraryVersion

the version number on the DotNetZip assembly, formatted as a string.

An enum that provides the different self-extractor flavors

A self-extracting zip archive that runs from the console or command line.

A self-extracting zip archive that presents a graphical user interface when it is executed..

The options for generating a self-extracting archive.

The type of SFX to create.

The command to run after extraction.

This is optional. Leave it empty (null in C# or Nothing in VB) to run no command after extraction. If it is non-empty, the SFX will execute the command specified in this string on the user's machine, and using the extract directory as the working directory for the process, after unpacking the archive. The program to execute can include a path, if you like. If you want to execute a program that accepts arguments, specify the program name, followed by a space, and then the arguments for the program, each separated by a space, just as you would on a normal command line. Example: program.exe arg1 arg2. The string prior to the first space will be taken as the program name, and the string following the first space specifies the arguments to the program. If you want to execute a program that has a space in the name or path of the file, surround the program name in double-quotes. The first character of the command line should be a double-quote character, and there must be a matching double-quote following the end of the program file name. Any optional arguments to the program follow that, separated by spaces. Example: "c:\project files\program name.exe" arg1 arg2. If the flavor of the SFX is SelfExtractorFlavor.ConsoleApplication, then the SFX starts a new process, using this string as the post-extract command line. The SFX waits for the process to exit. The exit code of the post-extract command line is returned as the exit code of the command-line self-extractor exe. A non-zero exit code is typically used to indicated a failure by the program. In the case of an SFX, a non-zero exit code may indicate a failure during extraction, OR, it may indicate a failure of the run-after-extract program if specified, OR, it may indicate the run-after-extract program could not be fuond. There is no way to distinguish these conditions from the calling shell, aside from parsing the output of the SFX. If you have Quiet set to true, you may not see error messages, if a problem occurs. If the flavor of the SFX is SelfExtractorFlavor.WinFormsApplication, then the SFX starts a new process, using this string as the post-extract command line, and using the extract directory as the working directory for the process. The SFX does not wait for the command to complete, and does not check the exit code of the program. If the run-after-extract program cannot be fuond, a message box is displayed indicating that fact. You can specify environment variables within this string, with a format like %NAME%. The value of these variables will be expanded at the time the SFX is run. Example: %WINDIR%\system32\xcopy.exe may expand at runtime to c:\Windows\System32\xcopy.exe. By combining this with the RemoveUnpackedFilesAfterExecute flag, you can create an SFX that extracts itself, runs a file that was extracted, then deletes all the files that were extracted. If you want it to run "invisibly" then set Flavor to SelfExtractorFlavor.ConsoleApplication, and set Quiet to true. You may also want to specify the default extract location, with DefaultExtractDirectory. If you set Flavor to SelfExtractorFlavor.WinFormsApplication, and set Quiet to true, then a GUI with progressbars is displayed, but it is "non-interactive" - it accepts no input from the user. Instead the SFX just automatically unpacks and exits.

The default extract directory the user will see when running the self-extracting archive.

Passing null (or Nothing in VB) here will cause the Self Extractor to use the the user's personal directory () for the default extract location. This is only a default location. The actual extract location will be settable on the command line when the SFX is executed. You can specify environment variables within this string, with %NAME%. The value of these variables will be expanded at the time the SFX is run. Example: %USERPROFILE%\Documents\unpack may expand at runtime to c:\users\melvin\Documents\unpack.

The name of an .ico file in the filesystem to use for the application icon for the generated SFX.

Normally, DotNetZip will embed an "zipped folder" icon into the generated SFX. If you prefer to use a different icon, you can specify it here. It should be a .ico file. This file is passed as the /win32icon option to the csc.exe compiler when constructing the SFX file.

Whether the ConsoleApplication SFX will be quiet during extraction.

This option affects the way the generated SFX runs. By default it is false. When you set it to true,... Flavor Behavior ConsoleApplication no messages will be emitted during successful operation. WinFormsApplication the SFX extracts automatically when the application is launched, with no additional user input. When you set it to false,... Flavor Behavior ConsoleApplication the extractor will emit a message to the console for each entry extracted. WinFormsApplication the SFX presents a forms UI and allows the user to select options before extracting.

Specify what the self-extractor will do when extracting an entry would overwrite an existing file.

The default behavvior is to Throw.

Whether to remove the files that have been unpacked, after executing the PostUnpackCommand.

If true, and if there is a PostUnpackCommand, and if the command runs successfully, then the files that the SFX unpacked will be removed, afterwards. If the command does not complete successfully (non-zero return code) then the files will not be removed. Setting this flag, and setting Flavor to SelfExtractorFlavor.ConsoleApplication, and setting Quiet to true, results in an SFX that extracts itself, runs a file that was extracted, then deletes all the files that were extracted, with no intervention by the user. You may also want to specify the default extract location, with DefaultExtractDirectory.

The file version number to embed into the generated EXE. It will show up, for example, during a mouseover in Windows Explorer.

The product version to embed into the generated EXE. It will show up, for example, during a mouseover in Windows Explorer.

You can use any arbitrary string, but a human-readable version number is recommended. For example "v1.2 alpha" or "v4.2 RC2". If you specify nothing, then there is no product version embedded into the EXE.

The copyright notice, if any, to embed into the generated EXE.

The description to embed into the generated EXE.

Use any arbitrary string. It will show up, for example, during a mouseover in Windows Explorer. If you specify nothing, then the string "DotNetZip SFX Archive" is embedded into the EXE as the description.

The product name to embed into the generated EXE.

Use any arbitrary string. It will show up, for example, while viewing properties of the EXE file in Windows Explorer.

Delegate in which the application writes the ZipEntry content for the named entry.

The name of the entry that must be written. The stream to which the entry data should be written. When you add an entry and specify a WriteDelegate, via , the application code provides the logic that writes the entry data directly into the zip file. This example shows how to define a WriteDelegate that obtains a DataSet, and then writes the XML for the DataSet into the zip archive. There's no need to save the XML to a disk file first.


             private void WriteEntry (String filename, Stream output)
             {
                 DataSet ds1 = ObtainDataSet();
                 ds1.WriteXml(output);
             }
             
             private void Run()
             {
                 using (var zip = new ZipFile())
                 {
                     zip.AddEntry(zipEntryName, WriteEntry);
                     zip.Save(zipFileName);
                 }
             }


             Private Sub WriteEntry (ByVal filename As String, ByVal output As Stream) 
                 DataSet ds1 = ObtainDataSet()
                 ds1.WriteXml(stream)
             End Sub
             
             Public Sub Run()
                 Using zip = New ZipFile
                     zip.AddEntry(zipEntryName, New WriteDelegate(AddressOf WriteEntry))
                     zip.Save(zipFileName)
                 End Using
             End Sub

Delegate in which the application opens the stream, just-in-time, for the named entry.

The name of the ZipEntry that the application should open the stream for. When you add an entry via , the application code provides the logic that opens and closes the stream for the given ZipEntry.

Delegate in which the application closes the stream, just-in-time, for the named entry.

The name of the ZipEntry that the application should close the stream for. The stream to be closed. When you add an entry via , the application code provides the logic that opens and closes the stream for the given ZipEntry.

Delegate for the callback by which the application tells the library the CompressionLevel to use for a file.

Using this callback, the application can, for example, specify that previously-compressed files (.mp3, .png, .docx, etc) should use a CompressionLevel of None, or can set the compression level based on any other factor.

In an EventArgs type, indicates which sort of progress event is being reported.

There are events for reading, events for saving, and events for extracting.

Indicates that a Add() operation has started.

Indicates that an individual entry in the archive has been added.

Indicates that a Add() operation has completed.

Indicates that a Read() operation has started.

Indicates that an individual entry in the archive is about to be read.

Indicates that an individual entry in the archive has just been read.

Indicates that a Read() operation has completed.

The given event reports the number of bytes read so far during a Read() operation.

Indicates that a Save() operation has started.

Indicates that an individual entry in the archive is about to be written.

Indicates that an individual entry in the archive has just been saved.

Indicates that a Save() operation has completed.

Indicates that the zip archive has been created in a temporary location during a Save() operation.

Indicates that the temporary file is about to be renamed to the final archive name during a Save() operation.

Indicates that the temporary file is has just been renamed to the final archive name during a Save() operation.

Indicates that the self-extracting archive has been compiled during a Save() operation.

The given event is reporting the number of source bytes that have run through the compressor so far during a Save() operation.

Indicates that an entry is about to be extracted.

Indicates that an entry has just been extracted.

Indicates that extraction of an entry would overwrite an existing filesystem file.

The given event is reporting the number of bytes written so far for the current entry during an Extract() operation.

Indicates that an ExtractAll operation is about to begin.

Indicates that an ExtractAll operation has completed.

Indicates that an error has occurred while saving a zip file. This generally means the file cannot be opened, because it has been removed, or because it is locked by another process. It can also mean that the file cannot be Read, because of a range lock conflict.

Provides information about the progress of a save, read, or extract operation. This is a base class; you will probably use one of the classes derived from this one.

The total number of entries to be saved or extracted.

The name of the last entry saved or extracted.

In an event handler, set this to cancel the save or extract operation that is in progress.

The type of event being reported.

Returns the archive name associated to this event.

The number of bytes read or written so far for this entry.

Total number of bytes that will be read or written for this entry. This number will be -1 if the value cannot be determined.

Provides information about the progress of a Read operation.

Provides information about the progress of a Add operation.

Provides information about the progress of a save operation.

Constructor for the SaveProgressEventArgs.

the name of the zip archive. whether this is before saving the entry, or after The total number of entries in the zip archive. Number of entries that have been saved. The entry involved in the event.

Number of entries saved so far.

Provides information about the progress of the extract operation.

Constructor for the ExtractProgressEventArgs.

the name of the zip archive. whether this is before saving the entry, or after The total number of entries in the zip archive. Number of entries that have been extracted. The entry involved in the event. The location to which entries are extracted.

Number of entries extracted so far. This is set only if the EventType is Extracting_BeforeExtractEntry or Extracting_AfterExtractEntry, and the Extract() is occurring witin the scope of a call to ExtractAll().

Returns the extraction target location, a filesystem path.

Provides information about the an error that occurred while zipping.

Returns the exception that occurred, if any.

Returns the name of the file that caused the exception, if any.

An enum providing the options when an error occurs during opening or reading of a file or directory that is being saved to a zip file.

This enum describes the actions that the library can take when an error occurs opening or reading a file, as it is being saved into a Zip archive. In some cases an error will occur when DotNetZip tries to open a file to be added to the zip archive. In other cases, an error might occur after the file has been successfully opened, while DotNetZip is reading the file. The first problem might occur when calling AddDirectory() on a directory that contains a Clipper .dbf file; the file is locked by Clipper and cannot be opened by another process. An example of the second problem is the ERROR_LOCK_VIOLATION that results when a file is opened by another process, but not locked, and a range lock has been taken on the file. Microsoft Outlook takes range locks on .PST files.

Throw an exception when an error occurs while zipping. This is the default behavior. (For COM clients, this is a 0 (zero).)

When an error occurs during zipping, for example a file cannot be opened, skip the file causing the error, and continue zipping. (For COM clients, this is a 1.)

When an error occurs during zipping, for example a file cannot be opened, retry the operation that caused the error. Be careful with this option. If the error is not temporary, the library will retry forever. (For COM clients, this is a 2.)

When an error occurs, invoke the zipError event. The event type used is . A typical use of this option: a GUI application may wish to pop up a dialog to allow the user to view the error that occurred, and choose an appropriate action. After your processing in the error event, if you want to skip the file, set on the ZipProgressEventArgs.CurrentEntry to Skip. If you want the exception to be thrown, set ZipErrorAction on the CurrentEntry to Throw. If you want to cancel the zip, set ZipProgressEventArgs.Cancel to true. Cancelling differs from using Skip in that a cancel will not save any further entries, if there are any. (For COM clients, the value of this enum is a 3.)

An enum that provides the various encryption algorithms supported by this library.

PkzipWeak implies the use of Zip 2.0 encryption, which is known to be weak and subvertible. A note on interoperability: Values of PkzipWeak and None are specified in PKWARE's zip specification, and are considered to be "standard". Zip archives produced using these options will be interoperable with many other zip tools and libraries, including Windows Explorer. Values of WinZipAes128 and WinZipAes256 are not part of the Zip specification, but rather imply the use of a vendor-specific extension from WinZip. If you want to produce interoperable Zip archives, do not use these values. For example, if you produce a zip archive using WinZipAes256, you will be able to open it in Windows Explorer on Windows XP and Vista, but you will not be able to extract entries; trying this will lead to an "unspecified error". For this reason, some people have said that a zip archive that uses WinZip's AES encryption is not actually a zip archive at all. A zip archive produced this way will be readable with the WinZip tool (Version 11 and beyond). There are other third-party tools and libraries, both commercial and otherwise, that support WinZip's AES encryption. These will be able to read AES-encrypted zip archives produced by DotNetZip, and conversely applications that use DotNetZip to read zip archives will be able to read AES-encrypted archives produced by those tools or libraries. Consult the documentation for those other tools and libraries to find out if WinZip's AES encryption is supported. In case you care: According to the WinZip specification, the actual AES key used is derived from the via an algorithm that complies with RFC 2898, using an iteration count of 1000. The algorithm is sometimes referred to as PBKDF2, which stands for "Password Based Key Derivation Function #2". A word about password strength and length: The AES encryption technology is very good, but any system is only as secure as the weakest link. If you want to secure your data, be sure to use a password that is hard to guess. To make it harder to guess (increase its "entropy"), you should make it longer. If you use normal characters from an ASCII keyboard, a password of length 20 will be strong enough that it will be impossible to guess. For more information on that, I'd encourage you to read this article. The WinZip AES algorithms are not supported with the version of DotNetZip that runs on the .NET Compact Framework. This is because .NET CF lacks the HMACSHA1 class that is required for producing the archive.

No encryption at all.

Traditional or Classic pkzip encryption.

WinZip AES encryption (128 key bits).

WinZip AES encryption (256 key bits).

An encryption algorithm that is not supported by DotNetZip.

FileSelector encapsulates logic that selects files from a source - a zip file or the filesystem - based on a set of criteria. This class is used internally by the DotNetZip library, in particular for the AddSelectedFiles() methods. This class can also be used independently of the zip capability in DotNetZip.

The FileSelector class is used internally by the ZipFile class for selecting files for inclusion into the ZipFile, when the method, or one of its overloads, is called. It's also used for the methods. Typically, an application that creates or manipulates Zip archives will not directly interact with the FileSelector class. Some applications may wish to use the FileSelector class directly, to select files from disk volumes based on a set of criteria, without creating or querying Zip archives. The file selection criteria include: a pattern to match the filename; the last modified, created, or last accessed time of the file; the size of the file; and the attributes of the file. Consult the documentation for for more information on specifying the selection criteria.

Retrieve the ZipEntry items in the ZipFile that conform to the specified criteria.

This method applies the criteria set in the FileSelector instance (as described in the ) to the specified ZipFile. Using this method, for example, you can retrieve all entries from the given ZipFile that have filenames ending in .txt. Normally, applications would not call this method directly. This method is used by the ZipFile class. This overload allows the selection of ZipEntry instances from the ZipFile to be restricted to entries contained within a particular directory in the ZipFile. Using the appropriate SelectionCriteria, you can retrieve entries based on size, time, and attributes. See for a description of the syntax of the SelectionCriteria string. The ZipFile from which to retrieve entries. the directory in the archive from which to select entries. If null, then all directories in the archive are used. a collection of ZipEntry objects that conform to the criteria.

Constructor that allows the caller to specify file selection criteria.

This constructor allows the caller to specify a set of criteria for selection of files. See for a description of the syntax of the selectionCriteria string. By default the FileSelector will traverse NTFS Reparse Points. To change this, use FileSelector(String, bool). The criteria for file selection.

Constructor that allows the caller to specify file selection criteria.

This constructor allows the caller to specify a set of criteria for selection of files. See for a description of the syntax of the selectionCriteria string. The criteria for file selection. whether to traverse NTFS reparse points (junctions).

Returns a string representation of the FileSelector object.

The string representation of the boolean logic statement of the file selection criteria for this instance.

Returns the names of the files in the specified directory that fit the selection criteria specified in the FileSelector.

This is equivalent to calling with recurseDirectories = false. The name of the directory over which to apply the FileSelector criteria. A collection of strings containing fully-qualified pathnames of files that match the criteria specified in the FileSelector instance.

Returns the names of the files in the specified directory that fit the selection criteria specified in the FileSelector, optionally recursing through subdirectories.

This method applies the file selection criteria contained in the FileSelector to the files contained in the given directory, and returns the names of files that conform to the criteria. The name of the directory over which to apply the FileSelector criteria. Whether to recurse through subdirectories when applying the file selection criteria. An collection of strings containing fully-qualified pathnames of files that match the criteria specified in the FileSelector instance.

The string specifying which files to include when retrieving.

Specify the criteria in statements of 3 elements: a noun, an operator, and a value. Consider the string "name != *.doc" . The noun is "name". The operator is "!=", implying "Not Equal". The value is "*.doc". That criterion, in English, says "all files with a name that does not end in the .doc extension." Supported nouns include "name" (or "filename") for the filename; "atime", "mtime", and "ctime" for last access time, last modfied time, and created time of the file, respectively; "attributes" (or "attrs") for the file attributes; "size" (or "length") for the file length (uncompressed); and "type" for the type of object, either a file or a directory. The "attributes", "type", and "name" nouns all support = and != as operators. The "size", "atime", "mtime", and "ctime" nouns support = and !=, and >, >=, <, <= as well. The times are taken to be expressed in "local time". Specify values for the file attributes as a string with one or more of the characters H,R,S,A,I,L in any order, implying file attributes of Hidden, ReadOnly, System, Archive, NotContextIndexed, and ReparsePoint (symbolic link) respectively. To specify a time, use YYYY-MM-DD-HH:mm:ss or YYYY/MM/DD-HH:mm:ss as the format. If you omit the HH:mm:ss portion, it is assumed to be 00:00:00 (midnight). The value for a size criterion is expressed in integer quantities of bytes, kilobytes (use k or kb after the number), megabytes (m or mb), or gigabytes (g or gb). The value for a name is a pattern to match against the filename, potentially including wildcards. The pattern follows CMD.exe glob rules: * implies one or more of any character, while ? implies one character. If the name pattern contains any slashes, it is matched to the entire filename, including the path; otherwise, it is matched against only the filename without the path. This means a pattern of "*\*.*" matches all files one directory level deep, while a pattern of "*.*" matches all files in all directories. To specify a name pattern that includes spaces, use single quotes around the pattern. A pattern of "'* *.*'" will match all files that have spaces in the filename. The full criteria string for that would be "name = '* *.*'" . The value for a type criterion is either F (implying a file) or D (implying a directory). Some examples: criteria Files retrieved name != *.xls any file with an extension that is not .xls name = *.mp3 any file with a .mp3 extension. *.mp3 (same as above) any file with a .mp3 extension. attributes = A all files whose attributes include the Archive bit. attributes != H all files whose attributes do not include the Hidden bit. mtime > 2009-01-01 all files with a last modified time after January 1st, 2009. ctime > 2009/01/01-03:00:00 all files with a created time after 3am (local time), on January 1st, 2009. size > 2gb all files whose uncompressed size is greater than 2gb. type = D all directories in the filesystem. You can combine criteria with the conjunctions AND, OR, and XOR. Using a string like "name = *.txt AND size >= 100k" for the selectionCriteria retrieves entries whose names end in .txt, and whose uncompressed size is greater than or equal to 100 kilobytes. For more complex combinations of criteria, you can use parenthesis to group clauses in the boolean logic. Absent parenthesis, the precedence of the criterion atoms is determined by order of appearance. Unlike the C# language, the AND conjunction does not take precendence over the logical OR. This is important only in strings that contain 3 or more criterion atoms. In other words, "name = *.txt and size > 1000 or attributes = H" implies "((name = *.txt AND size > 1000) OR attributes = H)" while "attributes = H OR name = *.txt and size > 1000" evaluates to "((attributes = H OR name = *.txt) AND size > 1000)". When in doubt, use parenthesis. Using time properties requires some extra care. If you want to retrieve all entries that were last updated on 2009 February 14, specify "mtime >= 2009-02-14 AND mtime < 2009-02-15". Read this to say: all files updated after 12:00am on February 14th, until 12:00am on February 15th. You can use the same bracketing approach to specify any time period - a year, a month, a week, and so on. The syntax allows one special case: if you provide a string with no spaces, it is treated as a pattern to match for the filename. Therefore a string like "*.xls" will be equivalent to specifying "name = *.xls". This "shorthand" notation does not work with compound criteria. There is no logic in this class that insures that the inclusion criteria are internally consistent. For example, it's possible to specify criteria that says the file must have a size of less than 100 bytes, as well as a size that is greater than 1000 bytes. Obviously no file will ever satisfy such criteria, but this class does not check for or detect such inconsistencies. Thrown in the setter if the value has an invalid syntax.

Indicates whether searches will traverse NTFS reparse points, like Junctions.

An enum for the options when extracting an entry would overwrite an existing file.

This enum describes the actions that the library can take when an Extract() or ExtractWithPassword() method is called to extract an entry to a filesystem, and the extraction would overwrite an existing filesystem file.

Throw an exception when extraction would overwrite an existing file. (For COM clients, this is a 0 (zero).)

When extraction would overwrite an existing file, overwrite the file silently. The overwrite will happen even if the target file is marked as read-only. (For COM clients, this is a 1.)

When extraction would overwrite an existing file, don't overwrite the file, silently. (For COM clients, this is a 2.)

When extraction would overwrite an existing file, invoke the ExtractProgress event, using an event type of . In this way, the application can decide, just-in-time, whether to overwrite the file. For example, a GUI application may wish to pop up a dialog to allow the user to choose. You may want to examine the property before making the decision. If, after your processing in the Extract progress event, you want to NOT extract the file, set on the ZipProgressEventArgs.CurrentEntry to DoNotOverwrite. If you do want to extract the file, set ZipEntry.ExtractExistingFile to OverwriteSilently. If you want to cancel the Extraction, set ZipProgressEventArgs.Cancel to true. Cancelling differs from using DoNotOverwrite in that a cancel will not extract any further entries, if there are any. (For COM clients, the value of this enum is a 3.)

An enum that specifies the source of the ZipEntry.

Default value. Invalid on a bonafide ZipEntry.

The entry was instantiated by calling AddFile() or another method that added an entry from the filesystem.

The entry was instantiated via or .

The ZipEntry was instantiated by reading a zipfile.

The content for the ZipEntry will be or was provided by the WriteDelegate.

The content for the ZipEntry will be obtained from the stream dispensed by the OpenDelegate. The entry was instantiated via .

The content for the ZipEntry will be or was obtained from a ZipOutputStream.

Read from the stream

the buffer to read the offset at which to start the number of bytes to read the number of bytes actually read

Write to the stream.

the buffer from which to write the offset at which to start writing the number of bytes to write

Provides a stream metaphor for generating zip files.

This class provides an alternative programming model to the one enabled by the class. Use this when creating zip files, as an alternative to the class, when you would like to use a Stream class to write the zip file. Some designs require a writable stream for output. This stream can be used to produce a zip file, as it is written. Both the ZipOutputStream class and the ZipFile class can be used to create zip files. Both of them support many of the common zip features, including Unicode, different compression levels, and ZIP64. For example, when creating a zip file via calls to the PutNextEntry() and Write() methods on the ZipOutputStream class, the caller is responsible for opening the file, reading the bytes from the file, writing those bytes into the ZipOutputStream, setting the attributes on the ZipEntry, and setting the created, last modified, and last accessed timestamps on the zip entry. All of these things are done automatically by a call to ZipFile.AddFile(). For this reason, the ZipOutputStream is generally recommended for when your application wants to emit the arbitrary data, not necessarily data from a filesystem file, directly into a zip file. Aside from the differences in programming model, there are other differences in capability between the two classes. ZipFile can be used to read and extract zip files, in addition to creating zip files. ZipOutputStream cannot read zip files. If you want to use a stream to read zip files, check out the class. ZipOutputStream does not support the creation of segmented or spanned zip files. ZipOutputStream cannot produce a self-extracting archive.

Create a ZipOutputStream, wrapping an existing stream.

The class is generally easier to use when creating zip files. The ZipOutputStream offers a different metaphor for creating a zip file, based on the class. On the desktop .NET Framework, DotNetZip can use a multi-threaded compression implementation that provides significant speed increases on large files, over 300k or so, at the cost of increased memory use at runtime. (The output of the compression is almost exactly the same size). But, the multi-threaded approach incurs a performance hit on smaller files. There's no way for the ZipOutputStream to know whether parallel compression will be beneficial, because the ZipOutputStream does not know how much data you will write through the stream. you may wish to set the property to zero, if you are compressing large files through ZipOutputStream. This will cause parallel compression to be used, always. The stream to wrap. It must be writable. This stream will be closed at the time the ZipOutputStream is closed. This example shows how to create a zip file, using the ZipOutputStream class.


             private void Zipup()
             {
                 if (filesToZip.Count == 0)
                 {
                     System.Console.WriteLine("Nothing to do.");
                     return;
                 }
            
                 using (var raw = File.Open(_outputFileName, FileMode.Create, FileAccess.ReadWrite ))
                 {
                     using (var output= new ZipOutputStream(raw))
                     {
                         output.Password = "VerySecret!";
                         output.Encryption = EncryptionAlgorithm.WinZipAes256;
            
                         foreach (string inputFileName in filesToZip)
                         {
                             System.Console.WriteLine("file: {0}", inputFileName);
            
                             output.PutNextEntry(inputFileName);
                             using (var input = File.Open(inputFileName, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Write ))
                             {
                                 byte[] buffer= new byte[2048];
                                 int n;
                                 while ((n= input.Read(buffer,0,buffer.Length)) > 0)
                                 {
                                     output.Write(buffer,0,n);
                                 }
                             }
                         }
                     }
                 }
             }


             Private Sub Zipup()
                 Dim outputFileName As String = "XmlData.zip"
                 Dim filesToZip As String() = Directory.GetFiles(".", "*.xml")
                 If (filesToZip.Length = 0) Then
                     Console.WriteLine("Nothing to do.")
                 Else
                     Using raw As FileStream = File.Open(outputFileName, FileMode.Create, FileAccess.ReadWrite)
                         Using output As ZipOutputStream = New ZipOutputStream(raw)
                             output.Password = "VerySecret!"
                             output.Encryption = EncryptionAlgorithm.WinZipAes256
                             Dim inputFileName As String
                             For Each inputFileName In filesToZip
                                 Console.WriteLine("file: {0}", inputFileName)
                                 output.PutNextEntry(inputFileName)
                                 Using input As FileStream = File.Open(inputFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
                                     Dim n As Integer
                                     Dim buffer As Byte() = New Byte(2048) {}
                                     Do While (n = input.Read(buffer, 0, buffer.Length) > 0)
                                         output.Write(buffer, 0, n)
                                     Loop
                                 End Using
                             Next
                         End Using
                     End Using
                 End If
             End Sub

Create a ZipOutputStream that writes to a filesystem file.

The class is generally easier to use when creating zip files. The ZipOutputStream offers a different metaphor for creating a zip file, based on the class. The name of the zip file to create. This example shows how to create a zip file, using the ZipOutputStream class.


             private void Zipup()
             {
                 if (filesToZip.Count == 0)
                 {
                     System.Console.WriteLine("Nothing to do.");
                     return;
                 }
            
                 using (var output= new ZipOutputStream(outputFileName))
                 {
                     output.Password = "VerySecret!";
                     output.Encryption = EncryptionAlgorithm.WinZipAes256;
            
                     foreach (string inputFileName in filesToZip)
                     {
                         System.Console.WriteLine("file: {0}", inputFileName);
            
                         output.PutNextEntry(inputFileName);
                         using (var input = File.Open(inputFileName, FileMode.Open, FileAccess.Read,
                                                      FileShare.Read | FileShare.Write ))
                         {
                             byte[] buffer= new byte[2048];
                             int n;
                             while ((n= input.Read(buffer,0,buffer.Length)) > 0)
                             {
                                 output.Write(buffer,0,n);
                             }
                         }
                     }
                 }
             }


             Private Sub Zipup()
                 Dim outputFileName As String = "XmlData.zip"
                 Dim filesToZip As String() = Directory.GetFiles(".", "*.xml")
                 If (filesToZip.Length = 0) Then
                     Console.WriteLine("Nothing to do.")
                 Else
                     Using output As ZipOutputStream = New ZipOutputStream(outputFileName)
                         output.Password = "VerySecret!"
                         output.Encryption = EncryptionAlgorithm.WinZipAes256
                         Dim inputFileName As String
                         For Each inputFileName In filesToZip
                             Console.WriteLine("file: {0}", inputFileName)
                             output.PutNextEntry(inputFileName)
                             Using input As FileStream = File.Open(inputFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
                                 Dim n As Integer
                                 Dim buffer As Byte() = New Byte(2048) {}
                                 Do While (n = input.Read(buffer, 0, buffer.Length) > 0)
                                     output.Write(buffer, 0, n)
                                 Loop
                             End Using
                         Next
                     End Using
                 End If
             End Sub

Create a ZipOutputStream.

See the documentation for the ZipOutputStream(Stream) constructor for an example. The stream to wrap. It must be writable. true if the application would like the stream to remain open after the ZipOutputStream has been closed.

Provides a string representation of the instance.

This can be useful for debugging purposes. a string representation of the instance.

Returns true if an entry by the given name has already been written to the ZipOutputStream.

The name of the entry to scan for. true if an entry by the given name has already been written.

Write the data from the buffer to the stream.

As the application writes data into this stream, the data may be compressed and encrypted before being written out to the underlying stream, depending on the settings of the and the properties. The buffer holding data to write to the stream. the offset within that data array to find the first byte to write. the number of bytes to write.

Specify the name of the next entry that will be written to the zip file.

Call this method just before calling , to specify the name of the entry that the next set of bytes written to the ZipOutputStream belongs to. All subsequent calls to Write, until the next call to PutNextEntry, will be inserted into the named entry in the zip file. If the used in PutNextEntry() ends in a slash, then the entry added is marked as a directory. Because directory entries do not contain data, a call to Write(), before an intervening additional call to PutNextEntry(), will throw an exception. If you don't call Write() between two calls to PutNextEntry(), the first entry is inserted into the zip file as a file of zero size. This may be what you want. Because PutNextEntry() closes out the prior entry, if any, this method may throw if there is a problem with the prior entry. This method returns the ZipEntry. You can modify public properties on the ZipEntry, such as , , and so on, until the first call to ZipOutputStream.Write(), or until the next call to PutNextEntry(). If you modify the ZipEntry after having called Write(), you may get a runtime exception, or you may silently get an invalid zip archive. This example shows how to create a zip file, using the ZipOutputStream class.


             private void Zipup()
             {
                 using (FileStream fs raw = File.Open(_outputFileName, FileMode.Create, FileAccess.ReadWrite ))
                 {
                     using (var output= new ZipOutputStream(fs))
                     {
                         output.Password = "VerySecret!";
                         output.Encryption = EncryptionAlgorithm.WinZipAes256;
                         output.PutNextEntry("entry1.txt");
                         byte[] buffer= System.Text.Encoding.ASCII.GetBytes("This is the content for entry #1.");
                         output.Write(buffer,0,buffer.Length);
                         output.PutNextEntry("entry2.txt");  // this will be zero length
                         output.PutNextEntry("entry3.txt");
                         buffer= System.Text.Encoding.ASCII.GetBytes("This is the content for entry #3.");
                         output.Write(buffer,0,buffer.Length);
                     }
                 }
             }

The name of the entry to be added, including any path to be used within the zip file. The ZipEntry created.

Dispose the stream

This method writes the Zip Central directory, then closes the stream. The application must call Dispose() (or Close) in order to produce a valid zip file. Typically the application will call Dispose() implicitly, via a using statement in C#, or a Using statement in VB. set this to true, always.

This is a no-op.

This method always throws a NotSupportedException.

ignored ignored ignored nothing

This method always throws a NotSupportedException.

ignored ignored nothing

This method always throws a NotSupportedException.

ignored

Sets the password to be used on the ZipOutputStream instance.

When writing a zip archive, this password is applied to the entries, not to the zip archive itself. It applies to any ZipEntry subsequently written to the ZipOutputStream. Using a password does not encrypt or protect the "directory" of the archive - the list of entries contained in the archive. If you set the Password property, the password actually applies to individual entries that are added to the archive, subsequent to the setting of this property. The list of filenames in the archive that is eventually created will appear in clear text, but the contents of the individual files are encrypted. This is how Zip encryption works. If you set this property, and then add a set of entries to the archive via calls to PutNextEntry, then each entry is encrypted with that password. You may also want to change the password between adding different entries. If you set the password, add an entry, then set the password to null (Nothing in VB), and add another entry, the first entry is encrypted and the second is not. When setting the Password, you may also want to explicitly set the property, to specify how to encrypt the entries added to the ZipFile. If you set the Password to a non-null value and do not set , then PKZip 2.0 ("Weak") encryption is used. This encryption is relatively weak but is very interoperable. If you set the password to a null value (Nothing in VB), Encryption is reset to None. Special case: if you wrap a ZipOutputStream around a non-seekable stream, and use encryption, and emit an entry of zero bytes, the Close() or PutNextEntry() following the entry will throw an exception.

The Encryption to use for entries added to the ZipOutputStream.

The specified Encryption is applied to the entries subsequently written to the ZipOutputStream instance. If you set this to something other than EncryptionAlgorithm.None, you will also need to set the to a non-null, non-empty value in order to actually get encryption on the entry. ZipOutputStream.Password ZipEntry.Encryption

Size of the work buffer to use for the ZLIB codec during compression.

Setting this may affect performance. For larger files, setting this to a larger size may improve performance, but I'm not sure. Sorry, I don't currently have good recommendations on how to set it. You can test it if you like.

The compression strategy to use for all entries.

Set the Strategy used by the ZLIB-compatible compressor, when compressing data for the entries in the zip archive. Different compression strategies work better on different sorts of data. The strategy parameter can affect the compression ratio and the speed of compression but not the correctness of the compresssion. For more information see .

The type of timestamp attached to the ZipEntry.

Set this in order to specify the kind of timestamp that should be emitted into the zip file for each entry.

Sets the compression level to be used for entries subsequently added to the zip archive.

Varying the compression level used on entries can affect the size-vs-speed tradeoff when compression and decompressing data streams or files. As with some other properties on the ZipOutputStream class, like , and , setting this property on a ZipOutputStream instance will cause the specified CompressionLevel to be used on all items that are subsequently added to the ZipOutputStream instance. If you do not set this property, the default compression level is used, which normally gives a good balance of compression efficiency and compression speed. In some tests, using BestCompression can double the time it takes to compress, while delivering just a small increase in compression efficiency. This behavior will vary with the type of data you compress. If you are in doubt, just leave this setting alone, and accept the default.

A comment attached to the zip archive.

The application sets this property to specify a comment to be embedded into the generated zip archive. According to PKWARE's zip specification, the comment is not encrypted, even if there is a password set on the zip file. The zip specification does not describe how to encode the comment string in a code page other than IBM437. Therefore, for "compliant" zip tools and libraries, comments will use IBM437. However, there are situations where you want an encoded Comment, for example using code page 950 "Big-5 Chinese". DotNetZip will encode the comment in the code page specified by , at the time of the call to Close() or Dispose.

Specify whether to use ZIP64 extensions when saving a zip archive.

The default value for the property is . is safest, in the sense that you will not get an Exception if a pre-ZIP64 limit is exceeded. You must set this property before calling Write().

Indicates whether ZIP64 extensions were used when saving the zip archive.

The value is defined only after the ZipOutputStream has been closed.

Whether the ZipOutputStream should use case-insensitive comparisons when checking for uniqueness of zip entries.

Though the zip specification doesn't prohibit zipfiles with duplicate entries, Sane zip files have no duplicates, and the DotNetZip library cannot create zip files with duplicate entries. If an application attempts to call with a name that duplicates one already used within the archive, the library will throw an Exception. This property allows the application to specify whether the ZipOutputStream instance considers ordinal case when checking for uniqueness of zip entries.

Indicates whether to encode entry filenames and entry comments using Unicode (UTF-8).

The PKWare zip specification provides for encoding file names and file comments in either the IBM437 code page, or in UTF-8. This flag selects the encoding according to that specification. By default, this flag is false, and filenames and comments are encoded into the zip file in the IBM437 codepage. Setting this flag to true will specify that filenames and comments that cannot be encoded with IBM437 will be encoded with UTF-8. Zip files created with strict adherence to the PKWare specification with respect to UTF-8 encoding can contain entries with filenames containing any combination of Unicode characters, including the full range of characters from Chinese, Latin, Hebrew, Greek, Cyrillic, and many other alphabets. However, because at this time, the UTF-8 portion of the PKWare specification is not broadly supported by other zip libraries and utilities, such zip files may not be readable by your favorite zip tool or archiver. In other words, interoperability will decrease if you set this flag to true. In particular, Zip files created with strict adherence to the PKWare specification with respect to UTF-8 encoding will not work well with Explorer in Windows XP or Windows Vista, because Windows compressed folders, as far as I know, do not support UTF-8 in zip files. Vista can read the zip files, but shows the filenames incorrectly. Unpacking from Windows Vista Explorer will result in filenames that have rubbish characters in place of the high-order UTF-8 bytes. Also, zip files that use UTF-8 encoding will not work well with Java applications that use the java.util.zip classes, as of v5.0 of the Java runtime. The Java runtime does not correctly implement the PKWare specification in this regard. As a result, we have the unfortunate situation that "correct" behavior by the DotNetZip library with regard to Unicode encoding of filenames during zip creation will result in zip files that are readable by strictly compliant and current tools (for example the most recent release of the commercial WinZip tool); but these zip files will not be readable by various other tools or libraries, including Windows Explorer. The DotNetZip library can read and write zip files with UTF8-encoded entries, according to the PKware spec. If you use DotNetZip for both creating and reading the zip file, and you use UTF-8, there will be no loss of information in the filenames. For example, using a self-extractor created by this library will allow you to unpack files correctly with no loss of information in the filenames. If you do not set this flag, it will remain false. If this flag is false, the ZipOutputStream will encode all filenames and comments using the IBM437 codepage. This can cause "loss of information" on some filenames, but the resulting zipfile will be more interoperable with other utilities. As an example of the loss of information, diacritics can be lost. The o-tilde character will be down-coded to plain o. The c with a cedilla (Unicode 0xE7) used in Portugese will be downcoded to a c. Likewise, the O-stroke character (Unicode 248), used in Danish and Norwegian, will be down-coded to plain o. Chinese characters cannot be represented in codepage IBM437; when using the default encoding, Chinese characters in filenames will be represented as ?. These are all examples of "information loss". The loss of information associated to the use of the IBM437 encoding is inconvenient, and can also lead to runtime errors. For example, using IBM437, any sequence of 4 Chinese characters will be encoded as ????. If your application creates a ZipOutputStream, does not set the encoding, then adds two files, each with names of four Chinese characters each, this will result in a duplicate filename exception. In the case where you add a single file with a name containing four Chinese characters, the zipfile will save properly, but extracting that file later, with any zip tool, will result in an error, because the question mark is not legal for use within filenames on Windows. These are just a few examples of the problems associated to loss of information. This flag is independent of the encoding of the content within the entries in the zip file. Think of the zip file as a container - it supports an encoding. Within the container are other "containers" - the file entries themselves. The encoding within those entries is independent of the encoding of the zip archive container for those entries. Rather than specify the encoding in a binary fashion using this flag, an application can specify an arbitrary encoding via the property. Setting the encoding explicitly when creating zip archives will result in non-compliant zip files that, curiously, are fairly interoperable. The challenge is, the PKWare specification does not provide for a way to specify that an entry in a zip archive uses a code page that is neither IBM437 nor UTF-8. Therefore if you set the encoding explicitly when creating a zip archive, you must take care upon reading the zip archive to use the same code page. If you get it wrong, the behavior is undefined and may result in incorrect filenames, exceptions, stomach upset, hair loss, and acne.

The text encoding to use when emitting entries into the zip archive, for those entries whose filenames or comments cannot be encoded with the default (IBM437) encoding.

The size threshold for an entry, above which a parallel deflate is used.

DotNetZip will use multiple threads to compress any ZipEntry, if the entry is larger than the given size. Zero means "always use parallel deflate", while -1 means "never use parallel deflate". If the entry size cannot be known before compression, as with any entry added via a ZipOutputStream, then Parallel deflate will never be performed, unless the value of this property is zero. A parallel deflate operations will speed up the compression of large files, on computers with multiple CPUs or multiple CPU cores. For files above 1mb, on a dual core or dual-cpu (2p) machine, the time required to compress the file can be 70% of the single-threaded deflate. For very large files on 4p machines the compression can be done in 30% of the normal time. The downside is that parallel deflate consumes extra memory during the deflate, and the deflation is slightly less effective. Parallel deflate tends to not be as effective as single-threaded deflate because the original data stream is split into multiple independent buffers, each of which is compressed in parallel. But because they are treated independently, there is no opportunity to share compression dictionaries, and additional framing bytes must be added to the output stream. For that reason, a deflated stream may be slightly larger when compressed using parallel deflate, as compared to a traditional single-threaded deflate. For files of about 512k, the increase over the normal deflate is as much as 5% of the total compressed size. For larger files, the difference can be as small as 0.1%. Multi-threaded compression does not give as much an advantage when using Encryption. This is primarily because encryption tends to slow down the entire pipeline. Also, multi-threaded compression gives less of an advantage when using lower compression levels, for example . You may have to perform some tests to determine the best approach for your situation. The default value for this property is -1, which means parallel compression will not be performed unless you set it to zero.

Always returns false.

Always returns true.

Always returns a NotSupportedException.

Setting this property always returns a NotSupportedException. Getting it returns the value of the Position on the underlying stream.

Issued when an ZipEntry.ExtractWithPassword() method is invoked with an incorrect password.

Base class for all exceptions defined by and throw by the Zip library.

Default ctor.