为Tableview的最后一行设置约束

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell(style: .default, reuseIdentifier: "Cell")
    
    // 判断是否为最后一行
    if indexPath.row == tableView.numberOfRows(inSection: indexPath.section) - 1 {
        // 创建约束
        let leadingConstraint = NSLayoutConstraint(item: cell.contentView, attribute: .leading, relatedBy: .equal, toItem: tableView, attribute: .leading, multiplier: 1, constant: 0)
        let trailingConstraint = NSLayoutConstraint(item: cell.contentView, attribute: .trailing, relatedBy: .equal, toItem: tableView, attribute: .trailing, multiplier: 1, constant: 0)
        let topConstraint = NSLayoutConstraint(item: cell.contentView, attribute: .top, relatedBy: .equal, toItem: tableView, attribute: .top, multiplier: 1, constant: 0)
        let bottomConstraint = NSLayoutConstraint(item: cell.contentView, attribute: .bottom, relatedBy: .equal, toItem: tableView, attribute: .bottom, multiplier: 1, constant: 0)
        
        // 添加约束
        cell.contentView.addConstraints([leadingConstraint, trailingConstraint, topConstraint, bottomConstraint])
    }
    
    // 设置其他行的内容
    
    return cell
}