Flex组件以几何中心作为中心进行缩放
控制BlurPopUpEffect控制弹出窗体的位置
var x:Number = (this.stage.stageWidth - eventView.width)/2;
var y:Number = (this.stage.stageHeight -

eventView.height)/2;

eventView.parentView = this;
//回调
eventView.callback = callbackHandler;
BlurPopUpEffect.showWindowInRedirectPosition

(eventView,this,true,x,y);
paddingLeft等属性默认值为0