TXXForm = class(TForm)protected
  procedure wmncpaint(var message: TNCPaintmessage); message wm_ncpaint;
...
end;procedure  txxxform.wmncpaint(var message: TNCPaintmessage); 
var
  dc: HDC;
begin
  dc := GetWindowDC(Handle);   // do something yourself!!  ReleaseDC(handle, DC);
end;