Flex上传单个文件

Flex上传单个文件的源码如下：

<?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="appComplete()">
	<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.events.CloseEvent;
		import flash.net.FileReference;
		import mx.controls.Alert;
		
		private var fileReference:FileReference;
		private var urlRequest:URLRequest;
		private function appComplete():void{
		fileReference = new FileReference();
		fileReference.addEventListener(Event.SELECT,onSelect); 
		fileReference.addEventListener(Event.COMPLETE,onComplete);
		urlRequest = new URLRequest("http://localhost:8666/Ashx/FileHandler.ashx");
		}
		
		//上传
		private function browse():void{
			var imageTypes:FileFilter = new FileFilter("图片 (*.jpg,*.jpeg,*.gif,*.png)","*.jpg; *.jpeg; *.gif; *.png");
			var allTypes:Array = new Array(imageTypes);
			try
			{
				fileReference.browse(allTypes);
			}
			catch(e:Error)
			{
				Alert.show(e.message+"&&"+e.getStackTrace());
			}
		}
		//文件被选择后调度
		private function onSelect(evt:Event):void{
		labelState.text="文件:"+fileReference.name+"      "+"大小:"+fileReference.size+"字节";
		fileReference.load();
		}
		//fileReference.load()运行成功后调度
		private function onComplete(evt:Event):void{
		image.source=fileReference.data;
		}
		//确认上传警告
		private function upload():void{
		fileReference.addEventListener(ProgressEvent.PROGRESS,onPROGRESS);
		fileReference.addEventListener(DataEvent.UPLOAD_COMPLETE_DATA,onUPLOAD_COMPLETE_DATA);
		Alert.show("上传？","确认",Alert.YES|Alert.NO,null,proceedWithUpload);
		}
		//执行上传
		private function proceedWithUpload(evt:CloseEvent):void{
		if(evt.detail == Alert.YES){
		fileReference.upload(urlRequest);
		}
		}
		//侦听上传进度
		private function onPROGRESS(evt:ProgressEvent):void{
		labelState.text = " 已上传 " + evt.bytesLoaded + " 字节，共 " + evt.bytesTotal + " 字节";
		fileReference.removeEventListener(ProgressEvent.PROGRESS,onPROGRESS);
		}
		//侦听成功上传
		private function onUPLOAD_COMPLETE_DATA(evt:DataEvent):void
		{
		if(evt.data == " Success"){
		Alert.show("上传成功");
		}
		fileReference.removeEventListener(DataEvent.UPLOAD_COMPLETE_DATA,onUPLOAD_COMPLETE_DATA);
		} 
		]]>
	</fx:Script>
	<mx:Button label="浏览文件" click="browse()"/>
	<mx:Button label="上传" click="upload()" x="78"/>
	<mx:Label id="labelState" y="30" width="369" height="19"/> 
	<mx:Image id="image" visible="true" x="50" y="138" width="150" height="180"/>
</s:Application>

其中处理上传并保存的那个地址所对应的页面的处理过程如下("http://localhost:8666/Ashx/FileHandler.ashx")：

 public class FileHandler : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            HttpPostedFile FileData = context.Request.Files["Filedata"];

            string result = "";
            try
            {
               // result = Path.GetFileName(FileData.FileName);//获得文件名
                string ext = Path.GetExtension(FileData.FileName);//获得文件扩展名
                string newFileName=Guid.NewGuid().ToString();
                string saveName =newFileName + ext;//实际保存文件名
                saveFile(FileData,context.Request.MapPath("~" + context.Request["folder"] + "/"),saveName);//保存文件
                result = saveName;
            }
            catch (Exception ex)
            {
                result = "";
            }

            context.Response.ContentType = "text/plain";
            context.Response.Write(result);
        }
        private void saveFile(HttpPostedFile postedFile,string phyPath,string saveName)
        {
            if (!Directory.Exists(phyPath))
            {
                Directory.CreateDirectory(phyPath);
            }
            try
            {
                postedFile.SaveAs(phyPath + saveName);
            }
            catch (Exception e)
            {
                throw new ApplicationException(e.Message);

            }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }