由于主管急着使用，以解燃眉之急，暂时为留出更多接口，待稍后修改再奉上。

package  {    import flash.display.Sprite;    import flash.net.URLLoader;    import flash.net.URLRequest;    import flash.events.Event;    import flash.events.ProgressEvent;        public class URLLoaderBar extends Sprite {        private var urlLoader:URLLoader;        private var loaded:Sprite;//loaded UI        private var total:Sprite;//total UI        public function URLLoaderBar(urlRequest:URLRequest) {            //draw total bar;            total.graphics.beginFill(0x000000,1);            total.graphics.drawRect(0,0,200,10);            total.graphics.endFill();            total.x = total.y = 0;            this.addChild(total);                        //draw loaded bar;            loaded.graphics.beginFill(0x00ff00,1);            loaded.graphics.drawRect(0,0,0,10);            loaded.graphics.endFill();            loaded.x = total.y = 0;            this.addChild(loaded);                        //start to listen            urlLoader = new URLLoader(urlRequest);            urlLoader.addEventListener(Event.OPEN, onOpenHandler);            urlLoader.addEventListener(ProgressEvent.PROGRESS, onProgressHandler);            urlLoader.addEventListener(Event.COMPLETE, onCompleteHandler);        }                private function onOpenHandler(event:Event):void{            trace('opened'+ urlLoader.bytesLoaded+'%')            }        private function onProgressHandler(event:ProgressEvent):void{            var amount:Number = (urlLoader.bytesLoaded/urlLoader.bytesTotal)*200;            loaded.graphics.clear();            loaded.graphics.beginFill(0x00ff00,1);            loaded.graphics.drawRect(0,0,amount,10);            loaded.graphics.endFill();            }        private function onCompleteHandler(event:Event):void{            trace('load complete'+ urlLoader.bytesLoaded+'%')            }    }}