iOS系统消息

一、键盘
1、UIKeyboardWillShowNotification 将要弹出键盘
2、UIKeyboardDidShowNotification 显示键盘
3、UIKeyboardWillHideNotification 将要隐藏键盘
4、UIKeyboardDidHideNotification 键盘已经隐藏
5、UIKeyboardWillChangeFrameNotification 键盘将要改变frame
6、UIKeyboardDidChangeFrameNotification 键盘已经改变frame

二、窗口
1、UIWindowDidBecomeVisibleNotification 窗口可见
2、UIWindowDidBecomeHiddenNotification 窗口隐藏
3、UIWindowDidBecomeKeyNotification
4、UIWindowDidResignKeyNotification
三、程序消息
1、UIApplicationDidBecomeActiveNotification 程序从后台激活
2、UIApplicationDidChangeStatusBarFrameNotification 状态栏frame改变
3、UIApplicationDidChangeStatusBarOrientationNotification 状态栏方向改变
4、UIApplicationDidEnterBackgroundNotification 进入后台
5、UIApplicationDidFinishLaunchingNotification 程序加载完成
6、UIApplicationDidReceiveMemoryWarningNotification 内存警告
7、UIApplicationProtectedDataDidBecomeAvailable
8、UIApplicationProtectedDataWillBecomeUnavailable
9、UIApplicationSignificantTimeChangeNotification 重要的时间变化
10、UIApplicationWillChangeStatusBarOrientationNotification 将要改变状态栏方向
11、UIApplicationWillChangeStatusBarFrameNotification 将要改变状态栏frame
12、UIApplicationWillEnterForegroundNotification
13、UIApplicationWillResignActiveNotification
14、UIApplicationWillTerminateNotification

四、电池、方向、传感器
1、UIDeviceBatteryLevelDidChangeNotification 电池电量
2、UIDeviceBatteryStateDidChangeNotification 电池状态
3、UIDeviceOrientationDidChangeNotification 方向
4、UIDeviceProximityStateDidChangeNotification 近距离传感器

五、音视频
1、MPMediaLibraryDidChangeNotification
2、MPMusicPlayerControllerPlaybackStateDidChangeNotification
3、MPMusicPlayerControllerNowPlayingItemDidChangeNotification
4、MPMusicPlayerControllerVolumeDidChangeNotification

六、其他 
1、NSUserDefaultsDidChangeNotification 用户默认设置变化
2   NSCurrentLocaleDidChangeNotification 本地化语言变化

iOS系统消息

原文：http://www.cnblogs.com/antlin/p/5688904.html