获取tableView中cell的按钮

如图所示：在点击cell中的按钮时，需要获取到当前的cell
之前我用的代理或者block，感觉有点麻烦，其实可以在控制器里面直接获取的

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *ID = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];
    }
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
    btn.frame = CGRectMake(10, 10, 50, 20);
    [btn setTitle:@"xxx" forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
    [cell addSubview:btn];
    return cell;
}
- (void)btnClick:(UIButton *)button {
    //如果button是添加到cell.contentView上，则 cell = [[button superview] superview];
    UITableViewCell *cell = (UITableViewCell *)[button superview];
    NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
//    NSLog(@"--%d",indexPath.row);
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:[NSString stringWithFormat:@"你点击的是第%ld个cell",indexPath.row] delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
    [alert show];
}