如何在AS3中引用swf中的元件、图片等资源以及布局信息

package
{
 //省略相关import代码
 
 public class BagDemo extends Sprite
 {
  private var _bagPanelLoader:Loader;//加载背包swf
 
  private var _mcBagPanel:MovieClip;//整个背包的影片剪辑
  private var _btnClose:SimpleButton;//关闭按钮
  private var _imgBagObj:Bitmap;//代表物品的位图
 
  //构造函数
  public function BagDemo()
  {
   loadBagSWF();//加载swf
  }
 
  //加载swf
  private function loadBagSWF():void
  {
   _bagPanelLoader = new Loader;
   /*添加事件响应，在swf加载完毕后再获取里面的资源*/
   _bagPanelLoader.contentLoaderInfo.addEventListener(Event.COMPLETE,onLoadComplete);
   /*新建加载器上下文，再新建应用程序域*/
   var context:LoaderContext = new LoaderContext();
   context.applicationDomain = new ApplicationDomain();
   /*开始加载swf*/
   _bagPanelLoader.load(new URLRequest("../bag.swf"),context);
  }
 
  private function onComplete(e:Event):void
  {
   /*获得加载器的应用程序域*/
   var domain:ApplicationDomain = (e.currentTarget as LoaderInfo).applicationDomain;
   /*可以这样获取bag.swf中的bag_panel影片剪辑*/
   var cls:Class = domain.getDefinition("bag_panel") as Class;
   _mcBagPanel = new cls() as MovieClip;
   addChild(_mcBagPanel);

   /*可以这样获取bag.swf中的btn_close按钮*/
   cls = domain.getDefinition("btn_close") as Class;
   _btnClose = new cls() as SimpleButton;
   addChild(_btnClose);
   
    /*在资源中有个AS链接为img_1091806133的位图，可以这样加载*/
   cls = domain.getDefinition("img_1091806133") as Class;
   var imgdataBagObj:BitmapData = new cls() as BitmapData;
   _imgBagObj = new Bitmap( imgdataBagObj );
   addChild(_imgBagObj);
  }
 }
}

//上面的代码已经将_mcBagPanel加载进来了，这里就直接用了。有上图可以看到关闭按钮btn_close的实例名为close_btn
var closeButton : SimpleButton = _mcBagPanel.getChildByName("close_btn") as SimpleButton;

//上面的代码已经将_mcBagPanel加载进来了，这里就直接用了。有上图可以看到关闭按钮btn_close的实例名为close_btn
var closeButton : SimpleButton = _mcBagPanel["close_btn"] as SimpleButton;