Flex4種方法與後臺交互的方法

一、HTTPService

    程序代碼：

 <?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">
<mx:Script>
<![CDATA[
private function initializeHandler(event:Event):void {
countriesService.send();
}
private function changeHandler(event:Event):void {
statesService.send();
}
]]>
</mx:Script>
<!-- 載入純靜態的xml數據 -->
<mx:HTTPService id="countriesService" url="http://www.rightactionscript.com/states/xml/countries.xml" />
<!-- 載入由php生成的xml數據 -->
<mx:HTTPService id="statesService" url="http://www.rightactionscript.com/states/xml/states.php">
<!-- 以下標籤就是要發送到服務端的數據了,可以這樣理解:有一個名爲country的變量,它的值爲花括號{}裏的內容 -->
<mx:request>
<country>{country.value}</country>
</mx:request>
</mx:HTTPService>
<mx:VBox>
<!-- 此控件的數據由第一個<mx:HTTPService/>控件接收的內容提供,並且由這個ComboBox控制着第二個ComboBox所要顯示的內容 -->
<mx:ComboBox id="country" dataProvider="{countriesService.lastResult.countries.country}"
change="changeHandler(event)" />
<!-- 下面的ComboBox已經綁定了{statesService.lastResult.states.state},隨它的數據改變而改變 -->
<mx:ComboBox dataProvider="{statesService.lastResult.states.state}" />
</mx:VBox>
</mx:Application>

    二、URLLoader

    程序代碼：

 <?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">
<mx:Script>
<![CDATA[
private var _countriesService:URLLoader;
private var _statesService:URLLoader;
private function initializeHandler(event:Event):void {
_countriesService = new URLLoader();
_countriesService.addEventListener(Event.COMPLETE, countriesCompleteHandler);
_countriesService.load(new URLRequest("http://www.rightactionscript.com/states/xml/countries.xml"));
_statesService = new URLLoader();
_statesService.addEventListener(Event.COMPLETE, statesCompleteHandler);
XML.ignoreWhitespace = true;
}
private function countriesCompleteHandler(event:Event):void {
var xml:XML = new XML(_countriesService.data);
country.dataProvider = xml.children();
}
private function statesCompleteHandler(event:Event):void {
var xml:XML = new XML(_statesService.data);
state.dataProvider = xml.children();
}
private function changeHandler(event:Event):void {
var request:URLRequest = new URLRequest("http://www.rightactionscript.com/states/xml/states.php");
var parameters:URLVariables = new URLVariables();
parameters.country = country.value;
request.data = parameters;
_statesService.load(request);
}
]]>
</mx:Script>
<mx:VBox>
<mx:ComboBox id="country" change="changeHandler(event)" />
<mx:ComboBox id="state" />
</mx:VBox>
</mx:Application>

    三、WebService 方法一

    程序代碼：

 <?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">
<mx:Script>
<![CDATA[
private function initializeHandler(event:Event):void {
statesService.getCountries();
}
private function changeHandler(event:Event):void {
statesService.getStates(country.value);
}
]]>
</mx:Script>
<mx:WebService id="statesService"
wsdl="http://www.rightactionscript.com/states/webservice/StatesService.php?wsdl">
<mx:operation name="getCountries" />
<mx:operation name="getStates" />
</mx:WebService>
<mx:VBox>
<mx:ComboBox id="country"
dataProvider="{statesService.getCountries.lastResult}" change="changeHandler(event)" />
<mx:ComboBox dataProvider="{statesService.getStates.lastResult}" />
</mx:VBox>
</mx:Application>

    四、WebService 方法二

    程序代碼：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">
<mx:Script>
<![CDATA[
private function initializeHandler(event:Event):void {
statesService.getCountries.send( );
}
private function changeHandler(event:Event):void {
statesService.getStates.send( );
}
]]>
</mx:Script>
<mx:WebService id="statesService" wsdl="http://www.rightactionscript.com/states/webservice/StatesService.php?wsdl">
<mx:operation name="getCountries" />
<mx:operation name="getStates">
<mx:request>
<country>{country.value}</country>
</mx:request>
</mx:operation>
</mx:WebService>
<mx:VBox>
<mx:ComboBox id="country"
dataProvider="{statesService.getCountries.lastResult}" change="changeHandler(event)" />
<mx:ComboBox dataProvider="{statesService.getStates.lastResult}" />
</mx:VBox>
</mx:Application>