Flex中操作XML(下)
?
四 在Flex中使用XML的例子
大的XML文档用来显示数据或者显示列表的情况比较多，比如显示数据时作为Datagrid的数据源，或者为List,Combobox,Tree等的显示列表。
?
当我们使用List或者Combobox的时候，往往会把XML对象转换为ArrayCollection对象，看下面的例子
外部Xml文件
view plaincopy to clipboardprint?
<books>?????????????????????
??? <book name="flex tutorial">?????????????????
??????? <price>30</price>?????????????
??????? <author>adobe</author>????????????
??? </book>?????????????????
??? <book name="air tutorial">??????????????????
??????? <price>40</price>?????????????
??????? <author>adobe</author>????????????
??? </book>?????????????????
??? <book name="java tutorial">?????????????????
??????? <price>50</price>?????????????
??????? <author>sun</author>??????????????
??? </book>?????????????????
</books>???????????????????
<books>?????
<book name="flex tutorial">????
?? <price>30</price>???
?? <author>adobe</author>???
</book>????
<book name="air tutorial">????
?? <price>40</price>???
?? <author>adobe</author>???
</book>????
<book name="java tutorial">????
?? <price>50</price>???
?? <author>sun</author>???
</book>????
</books>
Flex文件
view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>??????????????????
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"??????????????????
layout="absolute"????????????????
creationComplete="init()">????????????????
<mx:Script>???????????????
<!--[CDATA[??????????????????
????? import mx.collections.ArrayCollection;??????????????????
????? import mx.rpc.events.ResultEvent;???????????????
????? //用于数据绑定的ArrayCollection????????????????
????? [Bindable]private var externalData:ArrayCollection = new ArrayCollection();?????????????????
??????????????????????
????? private function init():void {??????????????????
????????? //发送请求??????????????????
????????? myService.send();???????????????
????? }???????????????
??????????????????????????
????? private function resultHandler(event:ResultEvent):void {????????????????
????????? //取得Xml对象中book节点的集合?????????????????
????????? externalData = event.result.books.book;?????????????????
????? }//断点处??????????????????
]]-->????????????????
</mx:Script>??????????????????
<!--创建Httpservice对象加载外部Xml-->?????????????????
<mx:HTTPService id="myService"???????????????
????? url="xmlFile.xml"???????????????
????? result="resultHandler(event)"/>??????????????????
<!--用于显示的list-->??????????????????
<mx:List id="datalist" dataProvider="{externalData}" labelField="name"/>??????????????????????????
</mx:Application>??????????????
<?xml version="1.0" encoding="utf-8"?>????
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"????
layout="absolute"????
creationComplete="init()">????
<mx:Script>????
<!--[CDATA[????
????? import mx.collections.ArrayCollection;????
????? import mx.rpc.events.ResultEvent;????
????? //用于数据绑定的ArrayCollection????
????? [Bindable]private var externalData:ArrayCollection = new ArrayCollection(); ????
???? ????
????? private function init():void {????
????????? //发送请求????
????????? myService.send();????
????? }????
???????? ????
????? private function resultHandler(event:ResultEvent):void {????
????????? //取得Xml对象中book节点的集合????
????????? externalData = event.result.books.book;????
????? }//断点处????
]]-->????
</mx:Script>????
<!--创建Httpservice对象加载外部Xml-->????
<mx:HTTPService id="myService"????
????? url="xmlFile.xml"????
????? result="resultHandler(event)"/>????
<!--用于显示的list-->????
<mx:List id="datalist" dataProvider="{externalData}" labelField="name"/>???????? ????
</mx:Application>
将上面的代码以debug模式执行，程序停在断点处，在variables视图中我们可以很清晰的看到程序HttpService对象在加载外部XML后已经把它转换成了ArrayCollection对象，如下图。这样就可以很轻松的将数据源绑定到显示列表对象List中。
??? </book>?????
??? <book name="air tutorial" price="40" author="adobe">????
??? </book>?????
</category>?????????
<category name="Java">??????????
??? <book name="java tutorial" price="50" author="sun">?????
??? </book>?????
</category>?????????
</books>???????
<books>
<category name="RIA">
<book name="flex tutorial" price="30" author="adobe">
</book>
<book name="air tutorial" price="40" author="adobe">
</book>
</category>??
<category name="Java">??
<book name="java tutorial" price="50" author="sun">
</book>
</category>??
</books>
Flex文件
view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>??????????????
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"??????????????
layout="absolute"????????????
creationComplete="myService.send()">??????????????
<mx:HTTPService id="myService"???????????
??? url="xmlFile.xml"?????????
??? resultFormat="e4x"/>???????
??????????????
<mx:XMLListCollection id="booktreesrc"?????????????
??? source="{myService.lastResult.category}"/>?????????
??????????????
<mx:Tree id="bookTree"?????????????
??? height="100%"?????????
??? dataProvider="{booktreesrc}"??????????
??? labelField="@name"/>???????
??????????????????????
</mx:Application>??????????
<?xml version="1.0" encoding="utf-8"?>???
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"???
layout="absolute"???
creationComplete="myService.send()">???
<mx:HTTPService id="myService"???
url="xmlFile.xml"??
resultFormat="e4x"/>??
???
<mx:XMLListCollection id="booktreesrc"???
source="{myService.lastResult.category}"/>??
???
<mx:Tree id="bookTree"???
height="100%"??
dataProvider="{booktreesrc}"??
labelField="@name"/>??
??????? ???
</mx:Application>
画面显示
