拖拽影片 - 使用 mouseMove

使用時機：一次移動多個DisplayObject

首先監聽要移動的Clip的MouseDown事件。
當Clip的MouseDown事件被觸發後，監聽Stage的MouseUp與MouseMove事件。
當Stage的MouseMove事件被觸發後，將滑鼠的X, Y座標設給Clip的X, Y座標。
當Stage的MouseUp事件被觸發後，移除Stage的MouseUp與MouseMove監聽事件。

import flash.display.Sprite;
 import flash.events.MouseEvent;
 
 /**
  * Mouse Move Drag Sample - use mouseMove event
  */
 public class MouseMoveDrag extends Sprite
 {
  private var ball:Ball;
  
  public function MouseMoveDrag() 
  {
   init();
  }
  
  private function init():void 
  {
   ball = new Ball;
   ball.x = 100;
   ball.y = 100;
   addChild(ball);
   ball.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
  }
  
  private function onMouseDown(evt:MouseEvent):void
  {
   stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
   stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
  }
  
  private function onMouseUp(evt:MouseEvent):void
  {
   stage.removeEventListener(MouseEvent.MOUSE_UP, onMouseUp);
   stage.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
  }
  
  private function onMouseMove(evt:MouseEvent):void
  {
   // reset the x and y point
   ball.x = mouseX;
   ball.y = mouseY;
  }
 }

參考書目：Keith Peters.《Function Actionscript 3.0 Animation》.Friends of ED