- (void)addTap{

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tap:)];
    tap.delegate = self;
    [_scrollView addGestureRecognizer:tap];
}

- (void)tap:(UITapGestureRecognizer *)tap{

    [self.view endEditing:YES];
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer
 
 *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch

{
    
    // 假設為UITableViewCellContentView（即點選了tableViewCell），則不截獲Touch事件
    if ([NSStringFromClass([touch.view class]) isEqualToString:@"tableViewCell"]) {
        return NO;
    }
    
    return  YES;
    
}