获取键盘高度- iOS

声明一个键盘高度属性

@property (nonatomic, assign)CGSize kbSize;

在 viewDidLoad 中视图注册通知中心
[self registerForKeyboardNotifications];

pragma mark -- 注册键盘的通知中心获取键盘的高度

//注册一个键盘的通知中心

 - (void)registerForKeyboardNotifications{
    
    //使用NSNotificationCenter 键盘出现时
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:) name:UIKeyboardDidShowNotification object:nil];

    }

//实现当键盘出现的时候计算键盘的高度大小。用于输入框显示位置

- (void)keyboardWasShown:(NSNotification*)aNotification
{
    
    NSDictionary* info = [aNotification userInfo];
    //kbSize键盘尺寸 (有width, height)
    self.kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;//键盘高度
    NSLog(@"hight_hitht:%f",self.kbSize.height);
    
    //self.view.frame = self.view.frame.size.height - self.kbSize.height;
    
    CGRect currentFrame = self.view.frame;
    CGFloat change =self.kbSize.height;
    currentFrame.origin.y = currentFrame.origin.y - change ;
    
    [UIView animateWithDuration:0.00000000001 animations:^{
        
        self.view.frame = currentFrame;
    }];
}`

// 视图将要消失时,移除通知中心
-(void)viewWillDisappear:(BOOL)animated
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}