iOS系统通知NSNotificationName

当程序被推送到后台时

UIApplicationDidEnterBackgroundNotification

当程序从后台将要重新回到前台时

UIApplicationWillEnterForegroundNotification

当程序完成载入后通知

UIApplicationDidFinishLaunchingNotification

应用程序转为激活状态时

UIApplicationDidBecomeActiveNotification

用户按下主屏幕按钮调用通知，并未进入后台状态

UIApplicationWillResignActiveNotification

内存较低时通知

UIApplicationDidReceiveMemoryWarningNotification

当程序将要退出时通知

UIApplicationWillTerminateNotification

当系统时间发生改变时通知

UIApplicationSignificantTimeChangeNotification

当StatusBar框方向将要变化时通知

UIApplicationWillChangeStatusBarOrientationNotification
// userInfo contains NSNumber with new orientation

当StatusBar框方向改变时通知

UIApplicationDidChangeStatusBarOrientationNotification
// userInfo contains NSNumber with old orientation

UIApplicationStatusBarOrientationUserInfoKey
// userInfo dictionary key for status bar orientation

当StatusBar框方向将要改变时通知

UIApplicationWillChangeStatusBarFrameNotification
// userInfo contains NSValue with new frame

系统状态栏已经发生变化通知

UIApplicationDidChangeStatusBarFrameNotification
// userInfo contains NSValue with old frame

UIApplicationStatusBarFrameUserInfoKey
// userInfo dictionary key for status bar frame

后台下载状态发生改变时通知（iOS7.0以后可用）

UIApplicationBackgroundRefreshStatusDidChangeNotification

受保护的文件当前变为不可用时通知

UIApplicationProtectedDataWillBecomeUnavailable

受保护的文件当前变为可用时通知

UIApplicationProtectedDataDidBecomeAvailable

截屏通知（iOS7.0以后可用）

UIApplicationUserDidTakeScreenshotNotification