用Objective中的NSNotificationCenter实现按键盘在屏幕上显示和隐藏ScrollView(上下键)

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

- (void)keyboardWillShow:(NSNotification *)notification {
    // 在这里添加显示ScrollView的代码
}

- (void)keyboardWillHide:(NSNotification *)notification {
    // 在这里添加隐藏ScrollView的代码
}

- (void)keyboardWillShow:(NSNotification *)notification {
    self.scrollView.hidden = NO;
}

- (void)keyboardWillHide:(NSNotification *)notification {
    self.scrollView.hidden = YES;
}