How to capture Windows Desktop to Bitmap

Here's a piece of Delphi code capable of capturing the Windows Desktop image into a TBitmap object:

procedure ScreenShot(DestBitmap : TBitmap) ;
var
  DC : HDC;
begin
  DC := GetDC (GetDesktopWindow) ;
  try
  DestBitmap.Width := GetDeviceCaps (DC, HORZRES) ;
  DestBitmap.Height := GetDeviceCaps (DC, VERTRES) ;
  BitBlt(DestBitmap.Canvas.Handle,
         0,
         0,
         DestBitmap.Width,
         DestBitmap.Height,
         DC,
         0,
         0,
         SRCCOPY) ;
  finally
  ReleaseDC (GetDesktopWindow, DC) ;
  end;
end;