Visual Basic 6.0

Transition from BeginCompressStringENC to FirstChunk/LastChunk

Provides instructions for replacing deprecated BeginCompressStringENC method calls with using FirstChunk/LastChunk properties. Visual Basic 6.0

Dim success As Long
success = 0

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

Dim sbCompressedBase64 As New ChilkatStringBuilder

Dim compress As New ChilkatCompression
compress.Algorithm = "deflate"
compress.Charset = "utf-8"
compress.EncodingMode = "base64"

Dim sbIndex As New ChilkatStringBuilder

' ----------------------------------------------------------------------------------
' This is the deprecated way of compressing in chunks using Begin/More/End methods..
' ----------------------------------------------------------------------------------
Dim i As Long
For i = 0 To 24
    ' Note: It is possible (and normal) for a BeginCompress* or MoreCompress* method to return
    ' an empty string (or 0 bytes).  When this happens, the input data is not lost.  It will be flushed
    ' in a subsequent call.
    sbIndex.Clear 
    success = sbIndex.AppendInt(i)
    If (i = 0) Then
        success = sbCompressedBase64.Append(compress.BeginCompressStringENC(sbIndex.GetAsString()))
    Else
        success = sbCompressedBase64.Append(compress.MoreCompressStringENC(sbIndex.GetAsString()))
    End If

    success = sbCompressedBase64.Append(compress.MoreCompressStringENC(": This is a line of data to be compressed..." & vbCrLf))
Next

' Flush any remaining output.
success = sbCompressedBase64.Append(compress.EndCompressStringENC())

Debug.Print "The base64 encoded compressed text:"
Debug.Print sbCompressedBase64.GetAsString()

' Decompress in one call:
Dim originalText As String
originalText = compress.DecompressStringENC(sbCompressedBase64.GetAsString())
Debug.Print originalText

' ----------------------------------------------------------------------------------
' This is new way of compressing in chunks using FirstChunk and LastChunk properties
' ----------------------------------------------------------------------------------

sbCompressedBase64.Clear 

compress.FirstChunk = 1
compress.LastChunk = 0

Dim bdCompressed As New ChilkatBinData
Dim sbUncompressedChunk As New ChilkatStringBuilder

For i = 0 To 24
    If (i = 24) Then
        compress.LastChunk = 1
    End If

    sbUncompressedChunk.Clear 
    success = sbUncompressedChunk.AppendInt(i)
    success = sbUncompressedChunk.Append(": This is a line of data to be compressed..." & vbCrLf)

    success = compress.CompressSb(sbUncompressedChunk,bdCompressed)

    compress.FirstChunk = 0
Next

Debug.Print "The base64 encoded compressed text:"
Debug.Print bdCompressed.GetEncoded("base64")

' Decompress in one call:
originalText = compress.DecompressStringENC(bdCompressed.GetEncoded("base64"))
Debug.Print originalText