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>