动态设置flash背景图片

import flash.display.*;
imgLoader("bg.jpg");
var loader:Loader;
function imgLoader(_path:String ):void{
	loader = new Loader;
	loader.contentLoaderInfo .addEventListener (Event.COMPLETE , imageComplete);
	loader.load(new URLRequest (_path));
}
function imageComplete(_evt:Event):void{
	var bitmapData:BitmapData  = _evt.target.content.bitmapData;
	graphics.beginBitmapFill (bitmapData, new Matrix(), true, true);
	graphics.drawRect (0, 0, stage.stageWidth, stage.stageHeight );

	loader.contentLoaderInfo .removeEventListener (Event.COMPLETE , imageComplete);
	loader = null;
}