iOS uitableivewCell 下划线顶格

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{

    cell.separatorInset = UIEdgeInsetsZero;

    cell.layoutMargins = UIEdgeInsetsZero;

    cell.preservesSuperviewLayoutMargins = NO;

}