在scrollview上添加点击并解决其子控件的点击无响应（如tableView）

- (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{
    // 假设为UITableViewCellContentView（即点击了tableViewCell），则不截获Touch事件
    if ([NSStringFromClass([touch.view class]) isEqualToString:@"tableViewCell"]) {
        return NO;
    }
    return  YES;
}