iOS-监听键盘高度变化

1.注册监听键盘弹出和收起的通知

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidHide:) name:UIKeyboardWillHideNotification object:nil];

2. 方法实现

#pragma mark --键盘弹出
- (void)keyboardWillChangeFrame:(NSNotification *)notification{
        //取出键盘动画的时间(根据userInfo的key----UIKeyboardAnimationDurationUserInfoKey)
    CGFloat duration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
    
    //取得键盘最后的frame(根据userInfo的key----UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 227}, {320, 253}}";)
    CGRect keyboardFrame = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    
    //计算控制器的view需要平移的距离
    CGFloat transformY = keyboardFrame.origin.y - self.view.frame.size.height;
    
    //执行动画
    [UIView animateWithDuration:duration animations:^{
        
    }];
}
#pragma mark --键盘收回
- (void)keyboardDidHide:(NSNotification *)notification{
    CGFloat duration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
    [UIView animateWithDuration:duration animations:^{
          
    }];
}

3.dealloc中移除通知

- (void)dealloc{
    [[NSNotificationCenter defaultCenter]removeObserver:self];
}