flex tree默认展开第一个节点

<?xml version="1.0" encoding="utf-8"?>

<mx:Application fontSize="12" xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()">

 <mx:Script>

  <![CDATA[

   public var treeXml: XML = <nodes name="所有">

          <node name="test01" code ="01" >

           <node name="test0101" code ="0101" />

           <node name="test0102" code ="0102" />

           <node name="test0103" code ="0103" />

          </node> 

          <node name="test02" code ="02" />

          <node name="test03" code ="03" />

          <node name="test04" code ="04" >

           <node name="test0401" code ="0401" />

           <node name="test0402" code ="0402" />

           <node name="test0403" code ="0403" />

          </node>          

          <node name="test05" code ="05" />

          </nodes>;

   private function init():void

   {

    tree.dataProvider = treeXml;

//默认展开第一个节点

    tree.openItems = treeXml;

   }

  ]]>

 </mx:Script>

 <mx:Tree id="tree" x="0" y="0" height="321" labelField="@name" width="261"></mx:Tree>

</mx:Application>