package
{
	import flash.display.Bitmap;
	import flash.display.Loader;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.net.URLLoader;
	import flash.net.URLLoaderDataFormat;
	import flash.net.URLRequest;
	import flash.utils.ByteArray;
	
	public class UrlImage extends Sprite
	{
		private var urlLoader:URLLoader;
		private var l:Loader;
		public function UrlImage()
		{
			super();
			if(stage)
			{
				init();
			}
			else
			{
				this.addEventListener(Event.ADDED_TO_STAGE,init);
			}
		}
		private function init(e:Event=null):void
		{
			urlLoader=new URLLoader();
			urlLoader.dataFormat=URLLoaderDataFormat.BINARY;
			urlLoader.addEventListener(Event.COMPLETE,onImageLoaded);
			urlLoader.load(new URLRequest("screen.png"));
		}
		
		private function onImageLoaded(event:Event):void
		{
			// TODO Auto-generated method stub
			trace(event.target.data is ByteArray)
			var ba:ByteArray=event.target.data as ByteArray;
			l=new Loader();
			l.contentLoaderInfo.addEventListener(Event.COMPLETE,onImage2Loaded);
			l.loadBytes(ba);
			urlLoader.removeEventListener(Event.COMPLETE,onImageLoaded);
			urlLoader=null;
		}
		
		protected function onImage2Loaded(event:Event):void
		{
			// TODO Auto-generated method stub
			var bitmap:Bitmap=event.target.content as Bitmap;
			addChild(bitmap);
			l.contentLoaderInfo.removeEventListener(Event.COMPLETE,onImage2Loaded);
			l=null;
		}
	}
}
as下输出true
js下输出false