测试时只有TextField，不知道怎么回事？
var _text:TextField=new TextField();
_text.border=true;
_text.background=true;
_text.x=200;
stage.addChild(_text);
var tt:Number;
var loader:Loader=new Loader();
loader.load(new URLRequest("hit.swf"));
stage.addChild(loader);
loader.addEventListener(ProgressEvent.PROGRESS,onprogress);
loader.addEventListener(Event.COMPLETE,oncomplete);
function onprogress(event:ProgressEvent):void{
       tt=Math.round(loader.contentLoaderInfo.bytesLoaded/loader.contentLoaderInfo.bytesTotal)*100;
       _text.text=String(tt)+"%";
       }
function oncomplete(event:Event):void{
       _text.text="100%";
       }

loader.contentLoadInfo.addEventListener(ProgressEvent.PROGRESS,onprogress);
loader.contentLoadInfo.addEventListener(Event.COMPLETE,oncomplete);