拖曳物件

package folder
{
	import flash.display.MovieClip;
	import flash.events.MouseEvent;
	import flash.events.Event;	
	
	public class Drag extends MovieClip
	{
	
		public function Drag():void
		{
			addEventListener(MouseEvent.MOUSE_DOWN, mouseDown);
		}
		
		protected function mouseDown(e:Event):void
		{
			startDrag();
			stage.addEventListener(MouseEvent.MOUSE_UP,mouseUp); //listen for mouse up on the stage, in case the finger/mouse moved off of the button accidentally when they release.
			addEventListener(Event.ENTER_FRAME,tick); //while the mouse is down, run the tick function once every frame as per the project frame rate
		}

		protected function mouseUp(e:Event):void 
		{
			removeEventListener(Event.ENTER_FRAME,tick);  //stop running the tick function every frame now that the mouse is up
			stage.removeEventListener(MouseEvent.MOUSE_UP,mouseUp); //remove the listener for mouse up
			stopDrag();
		}

		protected function tick(e:Event):void 
		{
			// do something while this obj is dragging.
			
		}

	}
	
}