[Flex] ButtonBar系列——flex3 labelFunction用户提供的函数，在每个项目上运行以确定其标签

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
                layout="vertical"
                verticalAlign="middle"
                backgroundColor="white">
    
    <mx:Script>
        <![CDATA[
            import mx.controls.ButtonBar;
            
            private var buttonBarXML:XML = describeType(ButtonBar);
            
            private function buttonBar_labelFunc(item:Object):String {
                var cat:String = item.category.toUpperCase();
                var len:uint = buttonBarXML.factory.child(item.data).length();
                return cat + " (" + len + ")";
            }
        ]]>
    </mx:Script>
    
    <mx:Array id="arr">
        <mx:Object category="Accessors" data="accessor" />
        <mx:Object category="Methods" data="method" />
    </mx:Array>
    <mx:ButtonBar id="buttonBar"  dataProvider="{arr}"  labelFunction="buttonBar_labelFunc" />
</mx:Application>