UIScrollview 键盘遮挡问题

#pragma mark - UIKeyboard Obscure Problem

- (void)handleKeyboardStuff {

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

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapScrollView:)];

[_scrollView addGestureRecognizer:tap];
}

- (void)keyboardWillShow:(NSNotification *)notification {

[self adjustInsetForKeyboardShow:YES notification:notification];
}

- (void)keyboardWillHide:(NSNotification *)notification {

[self adjustInsetForKeyboardShow:NO notification:notification];
}

- (void) tapScrollView:(id)sender {

[_scrollView endEditing:YES];
}

- (void)adjustInsetForKeyboardShow:(BOOL)show notification:(NSNotification *)notification {

NSDictionary *userInfo = notification.userInfo;
CGRect keyboardFrame = ((NSValue *)userInfo[UIKeyboardFrameBeginUserInfoKey]).CGRectValue;
CGFloat adjustmentHeight = (CGRectGetHeight(keyboardFrame) + 20.0) * (show ? 1 : -1);

UIEdgeInsets scrollInsets = _scrollView.contentInset;
scrollInsets.bottom += adjustmentHeight;
_scrollView.contentInset = scrollInsets;

UIEdgeInsets indicatorInsets = _scrollView.scrollIndicatorInsets;
indicatorInsets.bottom += adjustmentHeight;
_scrollView.scrollIndicatorInsets = indicatorInsets;

}

- (void)dealloc {

[[NSNotificationCenter defaultCenter] removeObserver:self];
}