Flex中本地图片上传前的预览

<?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"   creationComplete="init()"><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 --></fx:Declarations><fx:Script><![CDATA[import mx.utils.*;   import flash.net.*;   private var fileReference:FileReference=new FileReference();   private var byteArray:ByteArray;   private var bitmapData:BitmapData;   private var loader:Loader=new Loader();   private function init():void   {                  fileReference.addEventListener(Event.COMPLETE,fileReferenceCompleteHandler);   }   private function fileReferenceCompleteHandler(e:Event):void   {   byteArray = fileReference.data;   loader.contentLoaderInfo.addEventListener(Event.COMPLETE,loaderCompleteHandler);   loader.loadBytes(byteArray);   }   private function loaderCompleteHandler(e:Event):void   {   var bitmap:Bitmap = Bitmap(loader.content);   bitmapData = bitmap.bitmapData;   img.source = bitmap;   }   private function fileReferenceSelectHandler(e:Event):void   {   fileReference.load();   }   private function btnClick():void   {   fileReference.browse();   fileReference.addEventListener(Event.SELECT,fileReferenceSelectHandler);   }   ]]></fx:Script><mx:Panel width="456" height="345" horizontalCenter="0" verticalGap="0" horizontalAlign="center" verticalAlign="middle">   <mx:Image id="img" width="263" height="234"/>   <mx:Button label="选择..." click="btnClick()"/>   </mx:Panel></s:Application>