(Delphi DLL) Compress and Decompress a String

Demonstrates how to compress and decompress a string.

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
sb: HCkStringBuilder;
i: Integer;
compress: HCkCompression;
compressedBytes: HCkByteData;
compressedBase64: PWideChar;
decompressedString: PWideChar;

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

sb := CkStringBuilder_Create();

for i := 1 to 20 do
  begin
    CkStringBuilder_Append(sb,'This is the original uncompressed string.' + #13#10);
  end;

compress := CkCompression_Create();
CkCompression_putAlgorithm(compress,'deflate');
// Indicate that the utf-8 byte representation of the string should be compressed.
CkCompression_putCharset(compress,'utf-8');

compressedBytes := CkByteData_Create();
success := CkCompression_CompressString(compress,CkStringBuilder__getAsString(sb),compressedBytes);

// If the compressed data is desired in string format, then get the base64 representation of the bytes.
CkCompression_putEncodingMode(compress,'base64');
compressedBase64 := CkCompression__compressStringENC(compress,CkStringBuilder__getAsString(sb));
Memo1.Lines.Add('Compressed Bytes as Base64: ' + compressedBase64);

// Now decompress...
decompressedString := CkCompression__decompressString(compress,compressedBytes);
Memo1.Lines.Add('The original string after decompressing from binary compressed data:');
Memo1.Lines.Add(decompressedString);

// To decompress from Base64...
CkCompression_putEncodingMode(compress,'base64');
decompressedString := CkCompression__decompressStringENC(compress,compressedBase64);
Memo1.Lines.Add('The original string after decompressing from Base64:');
Memo1.Lines.Add(decompressedString);

CkStringBuilder_Dispose(sb);
CkCompression_Dispose(compress);
CkByteData_Dispose(compressedBytes);

end;