UIWindow小记

 If you choose to create a window in Interface Builder, be sure to select the Full Screen at Launch option in the Attributes inspector so that the window is sized appropriately for the current device. Because a window doesn’t receive touch events outside of its bounds and views aren’t clipped to the window’s bounds by default, an improperly sized window might not be able to deliver touch events to all its views.

原文：http://www.cnblogs.com/wangnan1979/p/4481504.html