载入外部图片作为背景平铺，MC剧中的方法
FLASH AS3 载入外部图片作为背景平铺，MC剧中的方法。
import flash.display.StageAlign;import flash.display.StageScaleMode;import flash.events.Event;import flash.display.Loader;import flash.net.URLRequest;import flash.display.Sprite;import flash.display.BitmapData;import flash.display.Bitmap;stage.align = StageAlign.TOP_LEFT;stage.scaleMode = StageScaleMode.NO_SCALE;stage.addEventListener(Event.RESIZE, resizeHandler);stage.dispatchEvent(new Event(Event.RESIZE));var _rootBackGround:Sprite;var backImage:MovieClip = new MovieClip();this.addChild(backImage);var loader:Loader = new Loader();loader.load(new URLRequest("bg.jpg"));loader.contentLoaderInfo.addEventListener(Event.COMPLETE,showLoadResult);function resizeHandler(e:Event):void{banner.y = stage.stageHeight / 2 - banner.height / 2;banner.x = stage.stageWidth / 2 - banner.width / 2;trace(banner.x + banner.y);}function showLoadResult(event:Event):void{var _bitmap:Bitmap = Bitmap(loader.content);var matrix:Matrix = new Matrix(1,0,0,1,this.stage.stageWidth / 2,this.stage.stageHeight / 2);var sampleSprite:Sprite = new Sprite();sampleSprite.graphics.beginBitmapFill(_bitmap.bitmapData, matrix , true , true);sampleSprite.graphics.drawRect(0, 0, 20000, 20000);sampleSprite.graphics.endFill();backImage.addChild(sampleSprite);setChildIndex(backImage,0);}