(Delphi ActiveX) 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 for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
sb: TChilkatStringBuilder;
i: Integer;
compressedStr: WideString;
bd: TChilkatBinData;
compress: TChilkatCompression;
decompressedStr: WideString;

begin
crypt := TChilkatCrypt2.Create(Self);

// Create data to be compressed.
sb := TChilkatStringBuilder.Create(Self);
i := 0;
while i < 25 do
  begin
    sb.Append('Hello World, this is a test.' + #13#10);
    i := i + 1;
  end;

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

Memo1.Lines.Add(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
bd := TChilkatBinData.Create(Self);
bd.AppendEncoded(compressedStr,'base64');

// Remove the 8-byte header.
bd.RemoveChunk(0,8);

// Decompress
compress := TChilkatCompression.Create(Self);
compress.Algorithm := 'bzip2';
compress.DecompressBd(bd.ControlInterface);

// Get the decompressed string.
decompressedStr := bd.GetString('utf-8');
Memo1.Lines.Add(decompressedStr);
end;