Flex与后台交互的4种方法

一、HTTPService

程序代码：

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1. <?xml version="1.0" encoding="utf-8"?>  


2. <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">  


3. <mx:Script>  


4. <!--[CDATA[  


5. private function initializeHandler(event:Event):void {  


6. countriesService.send();  


7. }  


8. private function changeHandler(event:Event):void {  


9. statesService.send();  


10. }  


11. ]]>  


12. </mx:Script>  


13. <!-- 载 入纯静态的xml数据 -->  


14. <mx:HTTPService id="countriesService" url="http://www.rightactionscript.com/states/xml/countries.xml" />  


15. <!-- 载入由php生成的xml数据 -->  


16. <mx:HTTPService id="statesService" url="http://www.rightactionscript.com/states/xml/states.php">  


17. <!-- 以下标签就是要发送到服务端的数据了,可以这样理解:有一个名为 country的变量,它的值为 花括号{}里的内容 -->  


18. <mx:request>  


19. <country>{country.value}</country>  


20. </mx:request>  


21. </mx:HTTPService>  


22. <mx:VBox>  


23. <!-- 此 控件的数据由第一个<mx:HTTPService/>控件接收的内容提供,并且由这个ComboBox控制着第二个ComboBox所要显 示的内容 -->  


24. <mx:ComboBox id="country" dataProvider="{countriesService.lastResult.countries.country}"  


25. change="changeHandler(event)" />  


26. <!-- 下面的ComboBox已经绑定了 {statesService.lastResult.states.state},随它的数据改变而改变 -->  


27. <mx:ComboBox dataProvider="{statesService.lastResult.states.state}" />  


28. </mx:VBox>  


29. </mx:Application>  

<?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> <!-- 载入纯静态的xml数据 --> <mx:HTTPService id="countriesService" url="http://www.rightactionscript.com/states/xml/countries.xml" /> <!-- 载入由php生成的xml数据 --> <mx:HTTPService id="statesService" url="http://www.rightactionscript.com/states/xml/states.php"> <!-- 以下标签就是要发送到服务端的数据了,可以这样理解:有一个名为country的变量,它的值为花括号{}里的内容 --> <mx:request> <country>{country.value}</country> </mx:request> </mx:HTTPService> <mx:VBox> <!-- 此控件的数据由第一个<mx:HTTPService/>控件接收的内容提供,并且由这个ComboBox控制着第二个ComboBox所要 显示的内容 --> <mx:ComboBox id="country" dataProvider="{countriesService.lastResult.countries.country}" change="changeHandler(event)" /> <!-- 下面的ComboBox已经绑定了{statesService.lastResult.states.state},随它的数据改变而改变 --> <mx:ComboBox dataProvider="{statesService.lastResult.states.state}" /> </mx:VBox> </mx:Application>  

二、URLLoader

程序代码：

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1. <?xml version="1.0" encoding="utf-8"?>  


2. <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">  


3. <mx:Script>  


4. <!--[CDATA[  


5. private var _countriesService:URLLoader;  


6. private var _statesService:URLLoader;  


7. private function initializeHandler(event:Event):void {  


8. _countriesService = new URLLoader();  


9. _countriesService.addEventListener(Event.COMPLETE, countriesCompleteHandler);  


10. _countriesService.load(new URLRequest("http://www.rightactionscript.com/states/xml/countries.xml"));  


11. _statesService = new URLLoader();  


12. _statesService.addEventListener(Event.COMPLETE, statesCompleteHandler);  


13. XML.ignoreWhitespace = true;  


14. }  


15. private function countriesCompleteHandler(event:Event):void {  


16. var xml:XML = new XML(_countriesService.data);  


17. country.dataProvider = xml.children();  


18. }  


19. private function statesCompleteHandler(event:Event):void {  


20. var xml:XML = new XML(_statesService.data);  


21. state.dataProvider = xml.children();  


22. }  


23. private function changeHandler(event:Event):void {  


24. var request:URLRequest = new URLRequest("http://www.rightactionscript.com/states/xml/states.php");  


25. var parameters:URLVariables = new URLVariables();  


26. parameters.country = country.value;  


27. request.data = parameters;  


28. _statesService.load(request);  


29. }  


30. ]]-->  


31. </mx:Script>  


32. <mx:VBox>  


33. <mx:ComboBox id="country" change="changeHandler(event)" />  


34. <mx:ComboBox id="state" />  


35. </mx:VBox>  


36. </mx:Application>  

<?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

程序代码：

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1. <?xml version="1.0" encoding="utf-8"?>  


2. <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">  


3. <mx:Script>  


4. <!--[CDATA[  


5. private function initializeHandler(event:Event):void {  


6. statesService.getCountries();  


7. }  


8. private function changeHandler(event:Event):void {  


9. statesService.getStates(country.value);  


10. }  


11. ]]-->  


12. </mx:Script>  


13. <mx:WebService id="statesService"  


14. wsdl="http://www.rightactionscript.com/states/webservice/StatesService.php?wsdl">  


15. <mx:operation name="getCountries" />  


16. <mx:operation name="getStates" />  


17. </mx:WebService>  


18. <mx:VBox>  


19. <mx:ComboBox id="country"  


20. dataProvider="{statesService.getCountries.lastResult}" change="changeHandler(event)" />  


21. <mx:ComboBox dataProvider="{statesService.getStates.lastResult}" />  


22. </mx:VBox>  


23. </mx:Application>  

<?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

程序代码：

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1. <?xml version="1.0" encoding="utf-8"?>  


2. <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="initializeHandler(event)">  


3. <mx:Script>  


4. <![CDATA[  


5. private function initializeHandler(event:Event):void {  


6. statesService.getCountries.send( );  


7. }  


8. private function changeHandler(event:Event):void {  


9. statesService.getStates.send( );  


10. }  


11. ]]-->  


12. </mx:Script>  


13. <mx:WebService id="statesService" wsdl="http://www.rightactionscript.com/states/webservice/StatesService.php?wsdl">  


14. <mx:operation name="getCountries" />  


15. <mx:operation name="getStates">  


16. <mx:request>  


17. <country>{country.value}</country>  


18. </mx:request>  


19. </mx:operation>  


20. </mx:WebService>  


21. <mx:VBox>  


22. <mx:ComboBox id="country"  


23. dataProvider="{statesService.getCountries.lastResult}" change="changeHandler(event)" />  


24. <mx:ComboBox dataProvider="{statesService.getStates.lastResult}" />  


25. </mx:VBox>  


26. </mx:Application>