Flex 与 JavaScript 交互

Flex 与 JavaScript 交互，主要依靠Flex的ExternalInterface，其提供了addCallBack和call方法.
下面的例子将演示Flex调用javascript，和javascript调用Flex

javascript代码：

function hello(param) {    
    alert(param);    
    return "jsp Hello:" + param;    
}    
   
function callFlexFunction() {    
    var x = document.getElementById("flexObject").flexHelloWorld("Hello", "world");    
    alert(x);    
}   

Flex代码：

<?xml version="1.0" encoding="utf-8"?>   
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"   
    initialize="initApp()">   
        
    <mx:Script>   
        <![CDATA    
            import mx.controls.Alert;    
            
            public function flexHelloWorld(param1:String, param2:String):String {    
                Alert.show("param1: " + param1 + "; param2:" + param2);    
                return "Hello " + param1 + param2;    
            }    
                
            public function initApp():void {    
                ExternalInterface.addCallback("flexHelloWorld", flexHelloWorld);    
            }    
                
            public function jspHello():void {    
                var s:String = ExternalInterface.call("hello", "Flex");    
                Alert.show(s);    
            }    
                
        ]]>   
    </mx:Script>   
        
    <mx:Button x="52" y="58" label="call javascript" click="jspHello()"/>   
        
</mx:Application>