專案的需要把Tree的父節點與子節點的樣式進行區分，效果如圖：

主程式程式碼：

<?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"   
         xmlns:appWidgets="appWidgets.*">  
  <fx:Script>  
    <![CDATA[        
      import mx.controls.Alert;  
      import mx.events.FlexEvent;  
      import mx.events.ListEvent;        
        
      [Bindable]  
      public var selectedNode:XML;  
      protected function myTree_changeHandler(event:ListEvent):void  
      {  
        // TODO Auto-generated method stub  
        selectedNode=Tree(event.target).selectedItem as XML;  
        var itemIsBranch:Boolean=myTree.dataDescriptor.isBranch(myTree.selectedItem);  
        Alert.show(
 
[email protected]+" "+itemIsBranch.toString() );  
      }  
        
      private function tree_labelFunc(item:XML):String{  
        var returnLabel:[email protected];  
//      var itemIsBranch:Boolean=myTree.dataDescriptor.isBranch(item);  
//      if(itemIsBranch){  
//        return returnLabel+=" (BRANCH)";            
//      }  
        
        if(myTree.dataDescriptor.hasChildren(item)){  
          returnLabel+=" (含有"+myTree.dataDescriptor.getChildren(item).length+"條內容)";            
        }  
          
        return returnLabel;  
      }  
        
    ]]>  
  </fx:Script>  
  
  <fx:Declarations>  
    <!-- 將非可視元素（例如服務、值物件）放在此處 -->  
      
    <fx:XMLList id="treeData">  
      <node label="Inbox">  
        <node label="Marketing"/>  
        <node label="日本不宣戰，可免受國際法制約，繼續從美國進口軍需品"/>  
        <node label="Personal"/>  
      </node>  
      <node label="古蹟建築">  
        <node label="天南地北天南地北天南地北天南地北"/>  
        <node label="Personal alskdjflajsdlfjalsjdfldfasdfsdf"/>  
      </node>  
      <node label="Spam"/>  
      <node label="Sent"/>  
      <node label="水域風觀">  
        <node label="天南地北天南地北天南地北天南地北天南地北天南地北天南地北天南地北"/>  
        <node label="Personal alskdjflajsdlfjalsjdfldfasdfsdf"/>  
      </node>  
        
  
    </fx:XMLList>  
      
  </fx:Declarations>  
      
    <mx:Tree id="myTree" width="300" height="400"   
         textAlign="left"  
         labelField="@label" dataProvider="{treeData}"  
         change="myTree_changeHandler(event)" labelFunction="tree_labelFunc"  
         wordWrap="true" variableRowHeight="true" depthColors="[#F1F9FF,#FFFFFF]"  
         itemRenderer="appWidgets.MyTreeItemRenderer"/>  
    
</s:Application>  
 

package appWidgets  
{  
  import mx.controls.treeClasses.TreeItemRenderer;  
  import mx.controls.treeClasses.TreeListData;  
    
  public class MyTreeItemRenderer extends TreeItemRenderer  
  {  
    public function MyTreeItemRenderer()  
    {  
      super();  
    }  
      
    override public function set data(value:Object):void{  
      super.data=value;  
      if(TreeListData(super.listData).hasChildren){  
        setStyle("color",0x343434);  
        setStyle("fontWeight","bold");  
        setStyle("fontSize",13);  
      }  
      else{  
        setStyle("color",0x009900);  
      }  
    }      
  }  
}