FLEX 树形菜单例子（二）

这个例子是用来选中子节点的同时展开父节点

<?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">
	<s:layout>
		<s:VerticalLayout horizontalAlign="center"/>
	</s:layout>
	<fx:Declarations>
		<!-- 将非可视元素（例如服务、值对象）放在此处 -->
		<fx:XML id="treeXML">
			<root label="监控点">
				<node label="厦门市软件园一期">
					<node label="望海路一" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="观日路一" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="前埔南路一" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="虎仔山路一" source="http://helpexamples.com/flash/video/lights_long.flv"/>
				</node>
				<node label="厦门市软件园二期">
					<node label="望海路二" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="观日路二" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="前埔南路二" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="虎仔山路二" source="http://helpexamples.com/flash/video/lights_long.flv"/>
				</node>
				<node label="厦门市软件园三期">
					<node label="望海路三" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="观日路三" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="前埔南路三" source="http://helpexamples.com/flash/video/cuepoints.flv"/>
					<node label="虎仔山路三" source="http://helpexamples.com/flash/video/lights_long.flv"/>
				</node>
			</root>
		</fx:XML>
	</fx:Declarations>
	<fx:Script>
		<![CDATA[
			import mx.events.ListEvent;
			private function selectedItem():void 
			{
				var label:String = textI.text;
				var node:XMLList = treeXML.child("node").child("node").(@label == label);
				expandParents(node[0]);
				tree.selectedItem = node[0];
				
			}
			
			private function expandParents(node:XML):void 
			{
				if (node && !tree.isItemOpen(node)) 
				{
					tree.expandItem(node,true);
					expandParents(node.parent()); 
				}
			}
			
			protected function tree_itemClickHandler(event:ListEvent):void
			{
				// TODO Auto-generated method stub
				var node:XML = tree.selectedItem as XML;
				trace(node.@label);
				textI.text = node.@label;
			}
			
		]]>
	</fx:Script>
	<s:TextInput text="望海路一" id="textI"/>
	<mx:Button label="选中" click="selectedItem()"/>
	<mx:Tree id="tree" width="300" height="400" dataProvider="{treeXML}" labelField="@label" showRoot="false" 
			 itemClick="tree_itemClickHandler(event)"/>
</s:Application>