- (void)viewDidLoad {
    self.automaticallyAdjustsScrollViewInsets = NO;
    //监听键盘的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrameNotify:) name:UIKeyboardWillChangeFrameNotification object:nil];
}
-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    _wasKeyboardManagerEnabled = [[IQKeyboardManager sharedManager]isEnabled];
    [[IQKeyboardManager sharedManager] setEnable:NO];
}
-(void)viewDidDisappear:(BOOL)animated {
{
    [super viewWillDisappear:animated];
    [[IQKeyboardManager sharedManager] setEnable:_wasKeyboardManagerEnabled];
}
/**
 *  点击了return按钮(键盘最右下角的按钮)就会调用
 */
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [self sendMessage];
    return YES;
}
/**
 *  当键盘改变了frame(位置和尺寸)的时候调用
 */
-(void)keyboardWillChangeFrameNotify:(NSNotification*)notify {
    // 0.取出键盘动画的时间
    CGFloat duration = [notify.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    // 1.取得键盘最后的frame
    CGRect keyboardFrame = [notify.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    // 2.计算控制器的view需要平移的距离
    CGFloat transformY = keyboardFrame.origin.y - self.view.frame.size.height;
    // 3.执行动画
    [UIView animateWithDuration:duration animations:^{
        self.myTableView.frame = CGRectMake(0, 0, SCREENW, SCREENH + transformY - self.inputView.height);
        self.tableViewBottomConstraint.constant = -transformY + 44;// tableView的bottom距父视图bottom的距离
        self.inputView.transform = CGAffineTransformMakeTranslation(0, transformY);
        [self scrollTableViewToBottom];
    }];
}
/**
 *  tableView快速滚动到底部
 */
- (void)scrollTableViewToBottom {
    if (self.messageFrames.count) {
        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:(self.messageFrames.count - 1) inSection:0];
       [self.myTableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
    }
}
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}