Flex如何将ComboBox下拉菜单中较长的内容用“…”代替

<?xml version="1.0" encoding="utf-8"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
        layout="vertical" 
        verticalAlign="top" 
        backgroundColor="white"> 
  
    <mx:Array id="arr"> 
        <mx:Object label="123456789123456789123456789." /> 
        <mx:Object label="abcdefghijklmnopqrstuvwsyz." /> 
        <mx:Object label="一二三四五六七八九十." /> 

    </mx:Array> 
  
    <mx:ComboBox id="combo1" 
            dataProvider="{arr}" 
            itemRenderer="mx.controls.Label" 
            width="100" /> 
  
</mx:Application>