iOS获取键盘的高度(在键盘出现,改变和消失时通知改变)

1. - (void)viewDidLoad

   {

       [super viewDidLoad];

       

       //增加监听，当键盘出现或改变时收出消息

       [[NSNotificationCenter defaultCenter] addObserver:self

                                                selector:@selector(keyboardWillShow:)

                                                    name:UIKeyboardWillShowNotification

                                                  object:nil];

       

       //增加监听，当键退出时收出消息

       [[NSNotificationCenter defaultCenter] addObserver:self

                                                selector:@selector(keyboardWillHide:)

                                                    name:UIKeyboardWillHideNotification

                                                  object:nil];

       

       

   }

   
   

   //当键盘出现或改变时调用

   - (void)keyboardWillShow:(NSNotification *)aNotification

   {

       //获取键盘的高度

       NSDictionary *userInfo = [aNotification userInfo];

       NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];

       CGRect keyboardRect = [aValue CGRectValue];

       float height = keyboardRect.size.height;

   }

   
   

   //当键退出时调用

   - (void)keyboardWillHide:(NSNotification *)aNotification

   {

       

   }