flex调用webservice返回xml格式字符串，并遍历

<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"    xmlns:s="library://ns.adobe.com/flex/spark"    xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" creationComplete="init()"><fx:Script><![CDATA[import mx.collections.ArrayCollection;import mx.controls.Alert;import mx.rpc.events.ResultEvent;import mx.rpc.soap.LoadEvent;import mx.rpc.soap.WebService;private var web:WebService;protected function init():void{web=new WebService();web.loadWSDL("http://10.19.1.55/staterain/rainSensor.asmx?WSDL");web.addEventListener(LoadEvent.LOAD,testConn);web.GetSensorState("-1");web.GetSensorState.addEventListener(ResultEvent.RESULT, getNum);}public function testConn(event:Event):void{lbl0.text="连接成功";}public function getNum(event:ResultEvent):void{//txt1.text=event.result.toString();var xmldata:XML=new XML(event.result);//for each ( var name:XML in xmldata.sensor ) {//Alert.show(name.sensorID);//} Alert.show(xmldata..sensorID);//for each ( var name:String in xmldata.sensor ) {//Alert.show(name);//}txt1.text=xmldata.toXMLString();}]]></fx:Script><s:layout><s:BasicLayout/></s:layout><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 --><fx:XML id="myData" xmlns=""><node lable="资料"><node lable="Music"><node lable="古典"/><node lable="摇滚"/><node lable="民歌"/></node><node lable="Movie"><node lable="法国"/><node lable="美国"/></node></node></fx:XML></fx:Declarations><s:Label x="18" y="17" text="标签" width="413" height="56" fontSize="36" id="lbl0"/><mx:Tree x="438" y="148" width="310" height="291" labelField="@lable" dataProvider="{myData}"  folderOpenIcon="@Embed(source='../flex_src/weather/1.gif')" defaultLeafIcon="@Embed(source='../flex_src/weather/0.gif')"  folderClosedIcon="@Embed(source='../flex_src/weather/2.gif')"></mx:Tree><s:TextInput x="73" y="165" width="357" height="484" id="txt1"/></s:Application>