Flex HTTPService 读取XML并显示在 Tree 中

1、Flex读取XML的两种方式：

<fx:Declarations>
??????? <!-- 1 -->
?? ???? <fx:XML id="xmldata" source="data/testdata.xml" format="e4x"/>
??????? <!-- 2 -->
?? ??? ?<s:HTTPService id="httpdata" url="data/testdata.xml" resultFormat="e4x" result="showXML(event)" />
</fx:Declarations>

2、HTTPService 读取XML并显示在 Tree 中

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" applicationComplete="init()"
			   xmlns:s="library://ns.adobe.com/flex/spark" 
			   xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
	<s:layout>
		<s:VerticalLayout horizontalAlign="center" verticalAlign="middle"/>
	</s:layout>
	<fx:Declarations>
		<!-- 将非可视元素（例如服务、值对象）放在此处 -->
		<s:HTTPService id="httpdata" url="data/testdata.xml" resultFormat="e4x" result="showXML(event)" />
	</fx:Declarations>
	
	<fx:Script>
		<![CDATA[
			import mx.rpc.events.ResultEvent;
			
			private function init():void {
				httpdata.send();
			}

			private function showXML(event:ResultEvent):void {
				var treeData:XML = event.result as XML;
				t.dataProvider = treeData;
			}

		]]>
	</fx:Script>
	
	<mx:Tree id="t" width="339" height="264" labelField="@label" />
	
</s:Application>

<?xml version="1.0" encoding="UTF-8"?>
<books label="books">
	<book label="book1">
		<id label="id">1001</id>
		<name label="name">book1</name>
		<price label="price">1</price>
	</book>
	<book label="book2">
		<id label="id">1002</id>
		<name label="name">book2</name>
		<price label="price">2</price>
	</book>
	<book label="book3">
		<id label="id">1003</id>
		<name label="name">book3</name>
		<price label="price">3</price>
	</book>
	<book label="book4">
		<id label="id">1004</id>
		<name label="name">book41</name>
		<price label="price">4</price>
	</book>
	<book label="book5">
		<id label="id">1005</id>
		<name label="name">book5</name>
		<price label="price">5</price>
	</book>
</books>