Flex 4 - 中心弹出窗口

Question

如何在flex 4中居中弹出窗口？

我试过了:

PopUpManager.addPopUp(AlertPopUp,DisplayObject(spark.components.Application), true);
PopUpManager.centerPopUp(AlertPopUp);

但转换Application-> DisplayObject时出现问题.

请帮忙 :)

Answer 1

PopUpManager.addPopUp(AlertPopUp, FlexGlobals.topLevelApplication as DisplayObject, true);
PopUpManager.centerPopUp(AlertPopUp);