(VB.NET UWP/WinRT) Compress Text Feed to Binary

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed binary data.

The purpose is to demonstrate the BeginCompressString, MoreCompressString, and EndCompressString methods.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Dim success As Boolean
Dim compressedData As New Chilkat.BinData
Dim compressedBytes() As Byte

Dim compress As New Chilkat.Compression
compress.Algorithm = "deflate"
compress.Charset = "utf-8"

Dim sbIndex As New Chilkat.StringBuilder

Dim i As Integer
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()
    sbIndex.AppendInt(i)
    If (i = 0) Then
        compressedBytes = Await compress.BeginCompressStringAsync(sbIndex.GetAsString())
    Else
        compressedBytes = Await compress.MoreCompressStringAsync(sbIndex.GetAsString())
    End If

    compressedData.AppendBinary(compressedBytes)
    compressedBytes = Await compress.MoreCompressStringAsync(": This is a line of data to be compressed..." & vbCrLf)
    compressedData.AppendBinary(compressedBytes)
Next

' Flush any remaining output.
compressedBytes = Await compress.EndCompressStringAsync()
compressedData.AppendBinary(compressedBytes)

' Show the compressed data in hex format:
Debug.WriteLine("The hex encoded compressed text:")
Debug.WriteLine(compressedData.GetEncoded("hex"))


' Now decompress in one call:
compressedBytes = compressedData.GetBinary()
Dim originalText As String = Await compress.DecompressStringAsync(compressedBytes)
Debug.WriteLine(originalText)