(VB.NET) Append Files to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append files to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim zip As New Chilkat.Zip

' The NewZip method only initializes the Zip object -- it does
' not create or write a .zip file.
Dim success As Boolean = zip.NewZip("notUsed.zip")
If (success <> True) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If



' Add a reference to a file.  This is the file that will
' be added to a pre-existing .zip archive.  
' Note: this does not read or compress the file contents --
' it simply adds a reference to the zip object.
Dim saveExtraPath As Boolean = False
success = zip.AppendOneFileOrDir("something.dat",saveExtraPath)
If (success <> True) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


' Appends the contents of the zip object to the preExisting.zip
' zip archive.  preExisting.zip is opened, and the files
' referenced by this zip object are streamed in, compressed,
' and appended to the end of the archive.
success = zip.QuickAppend("preExisting.zip")
If (success <> True) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Success!")


' Note: Additional files, directory trees, or in-memory data
' can be appended by calling AppendOneFileOrDir, AppendFiles,
' AppendString, AppendData, etc. multiple times.
' Whatever files and/or in-memory data that are referenced by
' this zip object will be appended to preExisting.zip when
' QuickAppend is called