Creating split zip files

Xceed Zip for .NET allows you to create split zip files which have the PkZip or Xceed Zip ActiveX naming conventions through the use of the SplitNameFormat and SplitSize properties of the ZipArchive class, as well as the option to create your own custom naming convention by also handling the DiskRequired event and changing the ZipFile property of the event arguments.

Basic steps

To create a split zip file, the following steps must be performed:

Retrieve a reference to a folder whose files will be added to the zip file, using either the DiskFolder, ZippedFolder, ZipArchive, MemoryFolder or IsolatedFolder classes. With Xceed Zip for .NET, a folder is a folder; it does not matter if it is located within a zip file, on disk or in memory.
Retrieve a reference to a new or existing zip file using the ZipArchive class. The last part or the part that has the .zip extension must be used when creating an instance of the ZipArchive class.
Set the SplitNameFormat and SplitSize properties of the ZipArchive object to the desired values. If you want to provide your own custom naming convention, set the SplitNameFormat property to SplitNameFormat.None. In this case, you must handle the DiskRequired event.

It is important to note that setting the SplitNameFormat and SplitSize properties will not automatically update the zip file. The zip file will only be updated at the next operation (for example, when files are added to the zip file or when the zip file's comment is modified ).
If you want to provide your own custom naming convention, then you will need to subscribe to the DiskRequired event. You can also use the DiskRequired event to change the location where the split zip file parts are created and the size of each split part.
Call the CopyFilesTo method to copy the entire contents of the folder to the zip file.

Demonstration

The following example demonstrates how to create a split zip file with the PkZip naming convention.

VB.NET Copy Code

VB.NET	Copy Code
`Imports Xceed.Zip Imports Xceed.Zip.Sfx Imports Xceed.FileSystem` `Dim zip As New ZipArchive( new DiskFile( "d:\split\test.zip" ) ) Dim source As New DiskFolder( "c:\windows\fonts" )` `zip.SplitNameFormat = SplitNameFormat.PkZip zip.SplitSize = 1000000` `source.CopyFilesTo( zip, True, True )`

Imports Xceed.Zip Imports Xceed.Zip.Sfx Imports Xceed.FileSystem

Dim zip As New ZipArchive( new DiskFile( "d:\split\test.zip" ) ) Dim source As New DiskFolder( "c:\windows\fonts" )

zip.SplitNameFormat = SplitNameFormat.PkZip zip.SplitSize = 1000000

source.CopyFilesTo( zip, True, True )

C# Copy Code

C#	Copy Code
`using Xceed.Zip; using Xceed.Zip.Sfx; using Xceed.FileSystem;` `ZipArchive zip = new ZipArchive( new DiskFile( @"d:\split\test.zip" ) ); DiskFolder source = new DiskFolder( @"c:\windows\fonts" );` `zip.SplitNameFormat = SplitNameFormat.PkZip; zip.SplitSize = 1000000;` `source.CopyFilesTo( zip, true, true );`

using Xceed.Zip; using Xceed.Zip.Sfx; using Xceed.FileSystem;

ZipArchive zip = new ZipArchive( new DiskFile( @"d:\split\test.zip" ) ); DiskFolder source = new DiskFolder( @"c:\windows\fonts" );

zip.SplitNameFormat = SplitNameFormat.PkZip; zip.SplitSize = 1000000;

source.CopyFilesTo( zip, true, true );

The next example demonstrates how to create a split zip file where each split part is located in a different folder and has the .zip extension.

VB.NET Copy Code

VB.NET	Copy Code
`Dim WithEvents zipEvents As New ZipEvents() AddHandler zipEvents.DiskRequired, AddressOf Me.OnDiskRequired` `' The first split zip file part will be located in the "1" folder. ' All subsequent parts will be located in folders representing their part number. Dim zip As New ZipArchive(zipEvents, Nothing, New DiskFile("d:\split\1\test.zip"))` `Dim source As New DiskFolder("c:\windows\fonts")` `zip.SplitNameFormat = SplitNameFormat.None zip.SplitSize = 1000000` `source.CopyFilesTo( zipEvents, Nothing, zip, True, True )` `' This method will handle the DiskRequired events that are raised. ' In it, we change the folder in which the part will be created. Private Sub OnDiskRequired(ByVal sender As Object, ByVal e As DiskRequiredEventArgs) e.ZipFile = New DiskFile(e.ZipFile.ParentFolder.ParentFolder.GetFolder((e.DiskNumber).ToString()).FullName + e.ZipFile.Name)` `e.Action = DiskRequiredAction.Continue End Sub`

Dim WithEvents zipEvents As New ZipEvents() AddHandler zipEvents.DiskRequired, AddressOf Me.OnDiskRequired

' The first split zip file part will be located in the "1" folder. ' All subsequent parts will be located in folders representing their part number. Dim zip As New ZipArchive(zipEvents, Nothing, New DiskFile("d:\split\1\test.zip"))

Dim source As New DiskFolder("c:\windows\fonts")

zip.SplitNameFormat = SplitNameFormat.None zip.SplitSize = 1000000

source.CopyFilesTo( zipEvents, Nothing, zip, True, True )

' This method will handle the DiskRequired events that are raised. ' In it, we change the folder in which the part will be created. Private Sub OnDiskRequired(ByVal sender As Object, ByVal e As DiskRequiredEventArgs) e.ZipFile = New DiskFile(e.ZipFile.ParentFolder.ParentFolder.GetFolder((e.DiskNumber).ToString()).FullName + e.ZipFile.Name)

e.Action = DiskRequiredAction.Continue End Sub

C# Copy Code

C#	Copy Code
`ZipEvents zipEvents = new ZipEvents(); zipEvents.DiskRequired += new DiskRequiredEventHandler( this.OnDiskRequired );` `Once the user has confirmed that the appropriate disk is in the drive, set the DiskRequiredAction to Continue. Setting the Action to Fail will not cause the whole operation to fail, but only the deleting step to be skipped.`

ZipEvents zipEvents = new ZipEvents(); zipEvents.DiskRequired += new DiskRequiredEventHandler( this.OnDiskRequired );

Once the user has confirmed that the appropriate disk is in the drive, set the DiskRequiredAction to Continue. Setting the Action to Fail will not cause the whole operation to fail, but only the deleting step to be skipped.

Things you should consider

The main questions you should ask yourself when copying items to a zip file are:

Do you want to filter (specify specific files and folders) the items that are to be added to the zip file? Use filters.
Do you want to display the status of the operation? See the Events topic.
Do you want to add items into a specific folder within the zip file? Create an instance of a ZippedFolder object rather than a ZipArchive object.
Do you only want to copy a specific file or folder? Use the CopyTo method.
Do you want to move items rather than copy them? Use the MoveTo and MoveFilesTo methods.
Do you want to change the location of the temporary folder. Set the ZipArchive's TempFolder or DefaultTempFolder property.
Do you only want to do basic zip file operations? Use the QuickZip class.
Do you want to modify the default extra headers that are stored to a zip file? Set the ZipArchive's DefaultExtraHeaders property.

All zip files will automatically be created in the Zip64 zip file format if the limitations of the regular Zip format are reached.