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Dateien komprimieren

Die Unit ZLib, die Delphi beiliegt, ermöglicht die ZIP-Komprimierung von Dateien.

uses ZLib, SysUtils;

procedure Compress(InputFileName, OutputFileName: string);
var InputStream, OutputStream: TFileStream;
  CompressionStream: ZLib.TCompressionStream;
begin
  InputStream:=TFileStream.Create(InputFileName, fmOpenRead);
  try
    OutputStream:=TFileStream.Create(OutputFileName, fmCreate);
    try
      CompressionStream:=TCompressionStream.Create(clMax, OutputStream);
      try
        CompressionStream.CopyFrom(InputStream, InputStream.Size);
      finally
        CompressionStream.Free;
      end;
    finally
      OutputStream.Free;
    end;
  finally
    InputStream.Free;
  end;
end;

Entpacken:

procedure Decompress(InputFileName, OutputFileName: string);
var InputStream, OutputStream: TFileStream;
  DeCompressionStream: ZLib.TDeCompressionStream;
  Buf: array[0..4095] of Byte;
  Count: Integer;
begin
  InputStream:=TFileStream.Create(InputFileName, fmOpenRead);
  try
    OutputStream:=TFileStream.Create(OutputFileName, fmCreate);
    try
      DecompressionStream := TDecompressionStream.Create(InputStream);
      try
        while true do
        begin
          Count := DecompressionStream.Read(Buf[0], SizeOf(Buf));
          if Count = 0 then
            break
          else
            OutputStream.Write(Buf[0], Count);
        end;
      finally
        DecompressionStream.Free;
      end;
    finally
      OutputStream.Free;
    end;
  finally
    InputStream.Free;
  end;
end;