How to get event or notification of the input method changing?(IOS5.1)

Question

（在IOS 5.1 Xcode 4.3中）当用户单击按钮切换键盘输入法时，如何进入此事件并确定输入法的状态？

Answer 1

When the input method changes, although the keyboard is already there, iOS will send the UIKeyboardDidShowNotification. You can register yourself for this notification like:

[[NSNotificationCenter defaultCenter] addObserver:self 
                                     selector:@selector(keyboardDidShow:) 
                                         name:UIKeyboardDidShowNotification
                                       object:nil];

Thats actually all you can do from my point of view! I'm not sure if it's possible to detect the current input method of the keyboard directly! Or maybte take a look at the following discussion: Detecting current iPhone input language !