Delphi-Help

function GetCheckSum(FileName: string): DWORD;  

var

  F: file of DWORD;  

  P: Pointer;  

  Fsize: DWORD;  

  Buffer: array[0..500] of DWORD;

begin

   FileMode := 0;

   AssignFile( F, FileName );

   Reset( F );

   Seek( F, FileSize( F ) div 2 );

   Fsize := FileSize( F ) - 1 - FilePos( F );

   if Fsize > 500 then Fsize := 500;

   BlockRead( F, Buffer, Fsize );

   Close( F );

   P := @Buffer;

   asm

      xor eax, eax

      xor ecx, ecx

      mov edi , p

      @again:

      add eax, [edi + 4*ecx]

      inc ecx

      cmp ecx, fsize

      jl @again

      mov @result, eax

   end;

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

   ShowMessage( IntToStr( GetCheckSum( 'c:\SetupDemoDB.exe' ) ) );

end;