Flex与靠山交互的4种方法 HTTPService、URLLoader、WebService详解

HTTPService

［折叠代码］
<?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>  

［折叠代码］

［折叠代码］
<?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>

［折叠代码］

［折叠代码］
<?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> 


［折叠代码］

WebService 方法二

［折叠代码］
<?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

［折叠代码］

FlashVars（单向传递）

• A.传递：在<embed 中设置 FlashVars=”name1=value1&name2=value2”
• B.接受:在as中写入 var value1=application.parameters.name1 即可