Deflate File

Demonstrates how to use the Deflate compression algorithm to compress a file. (The deflate compression algorithm is the most commonly used in the Zip archive file format.)

This code is capable of compressing any size file because the file data is compressed from input to output in a streaming mode. The output file contains only the deflated data (it is not a .zip, and there is no file structure or format).

Download the Chilkat Compression ActiveX here: ChilkatCompression.zip
Unzip and register the DLL with regsvr32. (This is a pre-release)

Dim compress As New ChilkatCompression

'  Any string argument automatically begins a 30-day trial.
Dim success As Long
success = compress.UnlockComponent("30-day trial")
If (success <> 1) Then
    MsgBox "Compression component unlock failed"
    Exit Sub
End If

compress.Algorithm = "deflate"

'  Deflate this XML file:
success = compress.CompressFile("hamlet.xml","hamletDeflate.dat")
If (success <> 1) Then
    MsgBox compress.LastErrorText
    Exit Sub
End If

'  Inflate back to the original:
success = compress.DecompressFile("hamletDeflate.dat","hamletInflated.xml")
If (success <> 1) Then
    MsgBox compress.LastErrorText
    Exit Sub
End If

Text1.Text = Text1.Text & "Success!" & vbCrLf