如何查找在组中单击的图形基元

我有一个组中有许多不同的图形基元。如果我点击组，我可以在MouseEvent（event）.currentTarget中获得对它的引用。但是我怎么知道我是否点击过图形原语？如何查找在组中单击的图形基元

例如代码：

<?xml version="1.0" encoding="utf-8"?> 
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
       xmlns:s="library://ns.adobe.com/flex/spark" 
       xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"> 

    <fx:Script> 
     <![CDATA[ 
      protected function group1_mouseDownHandler(event:MouseEvent):void { 
       trace("event target="+ event.target); 
       // traces the group 
      } 
     ]]> 
    </fx:Script> 


    <s:Group width="500" height="500" horizontalCenter="0" verticalCenter="0" 
      mouseDown="group1_mouseDownHandler(event)" 
      mouseEnabledWhereTransparent="true"> 


     <s:Rect x="10" width="100" height="100" radiusX="10" radiusY="10"> 
      <s:fill> 
       <s:SolidColor color="#ff0000"/> 
      </s:fill> 
     </s:Rect> 

     <s:Ellipse x="150" width="100" height="100"> 
      <s:fill> 
       <s:SolidColor color="#ff0000"/> 
      </s:fill> 
     </s:Ellipse> 

    </s:Group> 
</s:Application>

来源

2013-05-09 1.21 gigawatts