循环访问RadioButtonGroup中的各个子项的值.

numRadioButtons 属性and getRadioButtonAt() 方法.
示例：

代码：

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/20/looping-over-radiobutton-controls-in-a-radiobuttongroup-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;

            private function showAlert():void {
                var arr:Array = [];
                var rb:RadioButton;
                var idx:int;
                var len:int = radioGroup.numRadioButtons;

                for (idx=0; idx<len; idx++) {
                    rb = radioGroup.getRadioButtonAt(idx);
                    arr.push("index:" + idx + ", label:" + rb.label);
                }
                Alert.show(arr.join("\n"), "getRadioButtonAt():");
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button label="Click me" click="showAlert();" />
    </mx:ApplicationControlBar>

    <mx:RadioButtonGroup id="radioGroup" />

    <mx:VBox>
        <mx:RadioButton id="radioButton1" label="One" />
        <mx:RadioButton id="radioButton2" label="Two" />
        <mx:RadioButton id="radioButton3" label="Three" />
        <mx:RadioButton id="radioButton4" label="Four" />
        <mx:RadioButton id="radioButton5" label="Five" />
    </mx:VBox>

</mx:Application>