(VB.NET) Compress and Decompress Base64

Imagine we have data represented as a base64 string. This example demonstrates how to decode, compress, and re-encode to smaller base64 representing the compressed data.

Note: This example requires Chilkat v9.5.0.66 or greater.

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

Dim success As Boolean

Dim strBase64 As String = "VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K"

Dim compress As New Chilkat.Compression
compress.Algorithm = "deflate"

Dim binDat As New Chilkat.BinData
' Load the base64 data into a BinData object.
' This decodes the base64. The decoded bytes will be contained in the BinData.
binDat.AppendEncoded(strBase64,"base64")

' Compress the BinData.
compress.CompressBd(binDat)

' Get the compressed data in base64 format:
Dim compressedBase64 As String = binDat.GetEncoded("base64")
Debug.WriteLine("compressed base64:")
Debug.WriteLine(compressedBase64)

' The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=


' Now decompress:
binDat.Clear()
binDat.AppendEncoded(compressedBase64,"base64")
compress.DecompressBd(binDat)

Dim decompressedBase64 As String = binDat.GetEncoded("base64")
Debug.WriteLine("decompressed base64:")
Debug.WriteLine(decompressedBase64)

' The output is the original data:
' VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K