RadioButton控件的labelPlacement属性.
示例：
代码：
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/19/setting-the-label-placement-on-a-radiobuttongroup-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="middle"
backgroundColor="white">
<mx:ApplicationControlBar dock="true">
<mx:Form styleName="plain">
<mx:FormItem label="labelPlacement:">
<mx:ComboBox id="comboBox"
dataProvider="[left, right, top, bottom]"
selectedIndex="1" />
</mx:FormItem>
</mx:Form>
</mx:ApplicationControlBar>
<mx:RadioButtonGroup id="radioGroup"
labelPlacement="{comboBox.selectedItem}" />
<mx:HBox horizontalAlign="left" verticalGap="15">
<mx:RadioButton id="radioButton1"
label="Red"
group="{radioGroup}"
opaqueBackground="0xFF00FF" />
<mx:RadioButton id="radioButton2"
label="Orange"
group="{radioGroup}"
opaqueBackground="0xFF00FF" />
<mx:RadioButton id="radioButton3"
label="Yellow"
group="{radioGroup}"
opaqueBackground="0xFF00FF" />
<mx:RadioButton id="radioButton4"
label="Green"
group="{radioGroup}"
opaqueBackground="0xFF00FF" />
<mx:RadioButton id="radioButton5"
label="Blue"
group="{radioGroup}"
opaqueBackground="0xFF00FF" />
</mx:HBox>
</mx:Application>