MX Tree Control 事件

获取树控件的节点打开，选择的事件

<?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" >  
	
	<!-- ====== Properties of parent ======================= -->  
	<s:layout>
		<s:BasicLayout/>
	</s:layout>   
	
	<!-- ====== MetaData =================================== -->  
	
	<!-- ====== Styles ===================================== -->  
	
	<!-- ====== Script ===================================== -->  
	<fx:Script>
		<![CDATA[
			import flash.events.*;
			
			import mx.controls.*;
			import mx.events.*;
			
			protected function tree1_itemOpenHandler(event:TreeEvent):void
			{
				forOpen.text = event.item.@label
			}


			protected function tree1_changeHandler(event:ListEvent):void
			{
				var theData:String = ""
				if (event.currentTarget.selectedItem.@data) {
					theData = " Data: " + event.currentTarget.selectedItem.@data;
				}
				forChange.text = event.currentTarget.selectedItem.@label + theData;
			}
 
			protected function tree1_creationCompleteHandler(event:FlexEvent):void
			{
				tree1.expandItem(MailBox.getItemAt(0), true);
				forOpen.text=tree1.openItems[0].@label;
			}

		]]>
	</fx:Script>
	
	<!-- ====== Declarations =============================== -->  
	<fx:Declarations>
		<!-- 将非可视元素（例如服务、值对象）放在此处 -->
	</fx:Declarations>   
	
	<!-- ====== UI Components ============================== -->     
	<mx:Tree id="tree1"
			 labelField="@label"
			 showRoot="true"
			 width="160" x="16" y="99"
			 itemOpen="tree1_itemOpenHandler(event)"
			 change="tree1_changeHandler(event)" 
			 creationComplete="tree1_creationCompleteHandler(event)">
		<mx:XMLListCollection id="MailBox">
			<fx:XMLList>
				<node label="Mail" data="100">
					<node label="Inbox" data="70"/>
					<node label="Personal Folder" data="10">
						<node label="Business" data="2"/>
						<node label="Demo" data="3"/>
						<node label="Personal" data="0" isBranch="true" />
						<node label="Saved Mail" data="5" />
					</node>
					<node label="Sent" data="15"/>
					<node label="Trash" data="5"/>
				</node>
			</fx:XMLList>
		</mx:XMLListCollection>
	</mx:Tree>
	
	<mx:Form>
		<mx:FormItem label="Change Event:">
			<mx:Label id="forChange" width="150"/>
		</mx:FormItem>
		<mx:FormItem label="Open Event:">
			<mx:Label id="forOpen" width="150"/>
		</mx:FormItem>
	</mx:Form>
</s:Application>