bsp;            _circle.addEventListener(MouseEvent.MOUSE_DOWN,onDown);
             _circle.addEventListener(MouseEvent.MOUSE_UP,onUp);
            
         }
         private function onClick(event:MouseEvent):void{
             trace("circle clicked");
         }

         private function onDown(event:MouseEvent):void{
             _circle.startDrag();
         }
         private function onUp(event:MouseEvent):void{
             _circle.stopDrag();
         }
     }
}

现在就可以测试你的影片了。