1. //获取到得是屏幕的分辨率
private var ScreenHeight:Number = flash.system.Capabilities.screenResolutionY;
private var ScreenWidth:Number = flash.system.Capabilities.screenResolutionX;
2.窗口初始化时,用move()方法移动到中心
this.move(ScreenWidth/2-this.width/2,ScreenHeight/2-this.height/2); //(this当前窗体)