Delphi 使用 Indy 取得檔案 md5sum

uses
  IdHashMessageDigest, IdHash;

function md5sum(FileName: string): string;
var
 MyMD5: TIdHashMessageDigest5;
 Digest: T4x4LongWordRecord;
 Stream: TStream;
begin
  if FileExists(FileName) then begin
    MyMD5 := TIdHashMessageDigest5.Create;
    Stream := TFileStream.Create(FileName, fmOpenRead);
    try
      Digest := MyMD5.HashValue(Stream);
      Result := MyMD5.AsHex(Digest);
    finally
      Stream.Free;
      MyMD5.Free;
    end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ShowMessage(md5sum('c:\boot.ini')); // FileName
end;