Flex 2:URLLoader加载XML

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
    fontFamily="simsun" fontSize="12" 
    layout="absolute"  width="242" height="442" creationComplete="initApp()">
<mx:Script>
    <![CDATA[
        import mx.collections.ArrayCollection;
        import mx.rpc.events.ResultEvent;
        public var loader:URLLoader=new URLLoader();
        public var menus:XML=new XML();
        [Bindable]
        
        public function completeHandle(e:Event):void
        {
         menus=XML(loader.data);
         var results:XMLList=menus.node;
         tree.dataProvider=results;
        }
        public function initApp():void
        {
         var request:URLRequest=new URLRequest("TreeMenus.xml");
         loader.load(request);
         loader.addEventListener(Event.COMPLETE,completeHandle);
        }
    ]]>
</mx:Script>

    <mx:Tree id="tree" x="10" y="35" width="218" height="397" labelField="@label" />
    <mx:Label x="10" y="10" text="Tree Nodes From XML File"/>
</mx:Application>



//外部xml文件
<?xml version="1.0" encoding="utf-8"?>
<menus>
    <node label="商店一">
  <node label="摄相头一" data="shop1-1"/>
  <node label="摄相头二" data="shop1-2"/>
  <node label="摄相头三" data="shop1-3"/>
  <node label="摄相头四" data="shop1-4"/>
 </node>
 <node label="商店二">
  <node label="摄相头一" data="shop2-1"/>
  <node label="摄相头二" data="shop2-2"/>
  <node label="摄相头三" data="shop2-3"/>
  <node label="摄相头四" data="shop2-4"/>
 </node>
 <node label="商店三">
  <node label="摄相头一" data="shop3-1"/>
  <node label="摄相头二" data="shop3-2"/>
  <node label="摄相头三" data="shop3-3"/>
  <node label="摄相头四" data="shop3-4"/>
 </node>
</menus>