procedure TForm1.SpeedButton7Click(Sender: TObject);
var l,t:integer;
begin
ww:=ww *2 div 3; //利用本句和下一句来改变大小
hh:=hh *2 div 3; //...
l:=(form1.width-ww) div 2;
t:=(form1.height-hh) div 2;
form1.color:=clblack;
mediaplayer1.display:=Form1;
mediaplayer1.displayRect:=Rect(l,t,ww,hh);
mediaplayer1.play;
end;