Flex拖拽-List内部拖拽

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="creationHandler();">
	<mx:Script>
		<![CDATA[
		import mx.utils.ObjectUtil;
		import mx.events.DragEvent;
		import mx.collections.ArrayCollection;
		private function creationHandler():void {
			var collection:ArrayCollection = new ArrayCollection( ['Josh', 'Todd', 'Abey'] );
			contactList.dataProvider = collection;
		}
		
		]]>
	</mx:Script>
	
	<mx:Panel title="Contact List:" width="200" height="200"> 
		<mx:List id="contactList" width="100%" height="100%" dragEnabled="true" dropEnabled="true" dragMoveEnabled="true"/>
</mx:Panel>
</mx:WindowedApplication>