使用Flex创建动态进度条

<?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" creationComplete="InitApp()"  
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" width="435" height="208">   
  <fx:Script>   
<![CDATA[   
import mx.controls.Alert;   
import mx.controls.Image;   
import flash.net.URLLoader;   
import flash.net.URLRequest;   
import mx.managers.PopUpManager;   
import mx.controls.ProgressBar;  
private var valueNum:Number = 0;   
   //使用定时器处理progressBar 开始   
private var timer:Timer;   
    protected function InitApp():void{   
timer = new Timer(1);     
timer.addEventListener(TimerEvent.TIMER, OnTimeEvent);   
timer.start();   
}   
 private function OnTimeEvent(evt:TimerEvent):void{   
 valueNum = valueNum + 10;   
 var vaPercent:Number = valueNum / 100;   
 if(valueNum >= 10000)   
{   
progressBar.setProgress(valueNum, 10000);   
progressBar.label = "download completed";   
return;   
}   
  progressBar.setProgress(valueNum, 10000);