iOS 键盘监听与视图滚动

//通过设置该监听，用于获取键盘弹出时的轨迹属性及键盘frame
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
//通过设置该监听，用于获取键盘关闭时的轨迹属性及键盘frame
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:)
#pragma mark - 键盘事件监听
- (void)keyboardWillShow:(NSNotification *)notice {
    UIViewAnimationCurve _animationCurve;
    CGFloat _animationDuration;
    NSDictionary *userInfo = [notice userInfo];
    CGRect endFrame = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat _keyboardHeight = (endFrame.origin.y != kCCScreenHeight()) ? endFrame.size.height:0;
    if (!_keyboardHeight) return;
    
    CGRect beginRect = [[userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    CGRect endRect = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    if(!(beginRect.size.height > 0 && ( fabs(beginRect.origin.y - endRect.origin.y) > 0))) return;
    //动画执行时长
    _animationDuration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
//运行轨迹属性
    _animationCurve = [userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];
    //这样就可以与键盘动画无缝衔接了
    [UIView animateWithDuration:_animationDuration delay:0 options:(_animationCurve << 16 | UIViewAnimationOptionBeginFromCurrentState) animations:^{
        // 修改frame
    } completion:nil];
}

- (void)keyboardWillHide:(NSNotification *)noti {
    //获取键盘的高度
    NSDictionary *userInfo = [noti userInfo];
//    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];    
    CGFloat duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationCurve curve = [userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];
    
    [UIView animateWithDuration:duration delay:0 options:(curve << 16 | UIViewAnimationOptionBeginFromCurrentState) animations:^{
        // 修改frame
    } completion:nil];
}