- (void)viewDidAppear:(BOOL)animated {
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    [center addObserver:self selector:@selector(keyboardOnScreen:) name:UIKeyboardWillShowNotification object:nil];
    [center addObserver:self selector:@selector(keyboardHideScreen:) name:UIKeyboardWillHideNotification object:nil];
}
- (void)viewDidDisappear:(BOOL)animated {
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    [center removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [center removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

#pragma mark - 키보드
-(void)keyboardOnScreen:(NSNotification *)notification {
    //...
}
-(void)keyboardHideScreen:(NSNotification *)notification {
    //...
}

#pragma mark - 키보드
-(void)keyboardOnScreen:(NSNotification *)notification {
    NSDictionary *info  = notification.userInfo;
    NSValue      *value = info[UIKeyboardFrameEndUserInfoKey];
    
    CGRect rawFrame      = [value CGRectValue];
    CGRect keyboardFrame = [self.view convertRect:rawFrame fromView:nil]; /*키보드 프레임*/

    NSDictionary *userInfo = notification.userInfo;
    NSNumber *durationValue = userInfo[UIKeyboardAnimationDurationUserInfoKey];  /*키보드가 올라오는 동안의 시간*/
    NSTimeInterval animationDuration = durationValue.doubleValue;
    NSNumber *curveValue = userInfo[UIKeyboardAnimationCurveUserInfoKey];       /*키보드 애니메이션 옵션 효과 (ease)*/
    UIViewAnimationCurve animationCurve = curveValue.intValue;
    
    [UIView animateWithDuration:animationDuration delay:0.f options:animationCurve<<16 animations:^{
        // ...
    } completion:nil];
}

-(void)keyboardHideScreen:(NSNotification *)notification {
    NSDictionary *userInfo = notification.userInfo;
    NSNumber *durationValue = userInfo[UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval animationDuration = durationValue.doubleValue;
    NSNumber *curveValue = userInfo[UIKeyboardAnimationCurveUserInfoKey];
    UIViewAnimationCurve animationCurve = curveValue.intValue;


    
    [UIView animateWithDuration:animationDuration delay:0.f options:animationCurve<<16 animations:^{
        // ...
    } completion:nil];
}