Flex与后台交互的4种方法 HTTPService、URLLoader、WebService详解

HTTPService

Xml代码

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>

URLLoader

Xml代码

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>

WebService 方法一

Xml代码

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>

WebService 方法二

Xml代码

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>