(Visual Basic 6.0) Replacment for Deprecated Crypt2 Compress Functions

The Chilkat Crypt2 compression functions are deprecated and will be removed. This example shows how to duplicate the functionality using the Chilkat Compression class.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim crypt As New ChilkatCrypt2

' Create data to be compressed.
Dim sb As New ChilkatStringBuilder
Dim i As Long
i = 0
Do While i < 25
    success = sb.Append("Hello World, this is a test." & vbCrLf)
    i = i + 1
Loop

' Bzip2 compress the utf-8 byte representation of the string and return the compressed data as base64.
crypt.Charset = "utf-8"
crypt.EncodingMode = "base64"
Dim compressedStr As String
compressedStr = crypt.CompressStringENC(sb.GetAsString())

Debug.Print compressedStr

' Result: 4aeUs+4CAABCWmgzMUFZJlNZZ6znBgAAfNeAABJABQBAAIAmZJwAIABwUNNMAAUqoekYjMp4ixF1FlFxF8i5i1FvFwizF9iwi9RdxaizF7RZi6i0ixF3Fui/i7kinChIM9ZzgwA=

' The result contains an 8-byte header composed of a 4-byte magic number (0xB394A7E1) and a 4-byte length.
' Do the following to BZip2 decompress using Chilkat Compression
Dim bd As New ChilkatBinData
success = bd.AppendEncoded(compressedStr,"base64")

' Remove the 8-byte header.
success = bd.RemoveChunk(0,8)

' Decompress
Dim compress As New ChilkatCompression
compress.Algorithm = "bzip2"
success = compress.DecompressBd(bd)

' Get the decompressed string.
Dim decompressedStr As String
decompressedStr = bd.GetString("utf-8")
Debug.Print decompressedStr