#pragma mark - 键盘通知
- (void)addNoticeForKeyboard {

    //注册键盘出现的通知
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification object:nil];
    //注册键盘消失的通知
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

///键盘显示事件
- (void) keyboardWillShow:(NSNotification *)notification {
    //获取键盘高度，在不同设备上，以及中英文下是不同的
    CGFloat kbHeight = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;

    //计算出键盘顶端到inputTextView panel底端的距离(加上自定义的缓冲距离INTERVAL_KEYBOARD)
    CGFloat offset = (textView.frame.origin.y+textView.frame.size.height+INTERVAL_KEYBOARD) - (self.view.frame.size.height - kbHeight);

    // 取得键盘的动画时间，这样可以在视图上移的时候更连贯
    double duration = [[notification.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    //将视图上移计算好的偏移
    if(offset > 0) {
        [UIView animateWithDuration:duration animations:^{
            self.view.frame = CGRectMake(0.0f, -offset, self.view.frame.size.width, self.view.frame.size.height);
        }];
    }
}

///键盘消失事件
- (void) keyboardWillHide:(NSNotification *)notify {
    // 键盘动画时间
    double duration = [[notify.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    //视图下沉恢复原状
    [UIView animateWithDuration:duration animations:^{
        self.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
    }];
}