FLEX中Tree默认展开所有节点

这里分两种情况，一种是数据源在MXML文件中，如：
<mx:XML id="treeXML" format="e4x">
??????? <root>
??????????? <node label="通知通告管理" data="0">
??????????????? <node label="申报通知" data="1" />
??????????????? <node label="填表须知" data="1" />
??????????????? <node label="申报指南" data="1" />
??????????????? <node label="立项通告" data="1" />
??????????????? <node label="其它通知通告" data="1" />
??????????????? <node label="系统帮助" data="1" />
??????????? </node>
??????????? <node label="用户管理" data="0">?????
??????????????? <node label="申报单位用户管理" data="2" />
??????????????? <node label="归口部门用户管理" data="3" />
??????????????? <node label="审批用户管理" data="4" />
??????????? </node>
??????????? <node label="系统设置" data="0">
??????????? <node label="部门设置" data="5" />
??????????????? <node label="项目类别设置" data="5" />
??????????????? <node label="区域设置" data="5" />
??????????????? <node label="单位类别设置" data="5" />
??????????????? <node label="企业类型设置" data="5" />
??????????????? <node label="经济类型设置" data="5" />
??????????????? <node label="学历设置" data="5" />
??????????????? <node label="企业信用等级设置" data="5" />
??????????? </node>
??????? </root>
??? </mx:XML>

<mx:Tree id="myTree" dataProvider="{treeXML}" labelField="@label" showRoot="false" width="200" height="100%" />

这种情况下，只要在页面载入时creationComplete="initApp()"然后用
private function initApp():void {
????? for each(var item:XML in this.myTree.dataProvider)
???? this.myTree.expandChildrenOf(item,true);
???? }

就可以了。 但是还有一种情况，当数据源不包含在MXML文件中时，也就是当数据源是从后台程序获取时，直接用expandChildrenOf(item,true)不起作用，换一种方式。 <mx:HTTPService id="getTree" showBusyCursor="true" useProxy="false" resultFormat="e4x" url="users/getTree.asp" result="resultHandler(event)" fault="faultHandler(event)" /> <mx:Tree id="myTree" dataProvider="{getTree.lastResult}" width="200" height="100%" /> 然后在Script里面写 private var xmlData : XML; ???? ???? private function resultHandler(event:ResultEvent):void???? { ??????????????? xmlData = XML(event.result); ??????????????? myTree.showRoot = false; ??????????????? myTree.dataProvider = xmlData; ??????????????? myTree.labelField = "@label"; ??????????????? myTree.callLater(expandTree); ??????????? } ???????????? ???? private function expandTree():void{ ???? myTree.expandChildrenOf(xmlData,true); ??? }