如何为UITableView部分创建自定义背景？

创建UITableViewCell子类并添加UIView白色。为该单元格添加视图的左右填充。向此新添加的视图添加UILabel和其他UI元素，而不是添加cell或其contentView。将cell背景色设置为UIColor.groupTableViewBackground

class CustomCell: UITableViewCell {

    let bgView = UIView()
    let label = UILabel()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        commonInit()
    }
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    func commonInit() {

        backgroundColor = .groupTableViewBackground

        bgView.backgroundColor = .white
        bgView.translatesAutoresizingMaskIntoConstraints = false
        addSubview(bgView)

        label.translatesAutoresizingMaskIntoConstraints = false
        bgView.addSubview(label)

        bgView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        bgView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
        bgView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10).isActive = true
        bgView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -10).isActive = true

        label.heightAnchor.constraint(equalToConstant: 30).isActive = true
        label.topAnchor.constraint(equalTo: bgView.topAnchor, constant: 5).isActive = true
        label.bottomAnchor.constraint(equalTo: bgView.bottomAnchor, constant: -5).isActive = true
        label.leadingAnchor.constraint(equalTo: bgView.leadingAnchor, constant: 5).isActive = true
        label.trailingAnchor.constraint(equalTo: bgView.trailingAnchor, constant: -5).isActive = true
    }
}

在您的中使用此单元格类tableView。并将您的视图控制器背景色和tableView背景色设置为UIColor.groupTableViewBackground

在cellForRowAt检查是否细胞是一节的第一个或最后一个单元格。如果它是该部分的第一个单元格，则将角半径应用到左上角，右上角。如果单元格是该部分的最后一个单元格，则将角半径应用于左下角和右下角。如果单元格在中间，则删除拐角半径。

class TableViewController: UITableViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.backgroundColor = .groupTableViewBackground
        tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
        tableView.separatorInset = UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 10)
        tableView.tableFooterView = UIView()
    }
    // MARK: - Table view data source
    override func numberOfSections(in tableView: UITableView) -> Int {
        return 2
    }
    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return "Section \(section) Title"
    }
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 4
    }
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell") as? CustomCell
            ?? CustomCell(style: .default, reuseIdentifier: "CustomCell")
        if indexPath.row == 0 {//first cell of this section
            cell.bgView.layer.cornerRadius = 15.0
            cell.bgView.layer.masksToBounds = true
            cell.bgView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
        } else if indexPath.row == tableView.numberOfRows(inSection: indexPath.section)-1 {//last cell of this section
            cell.bgView.layer.cornerRadius = 15.0
            cell.bgView.layer.masksToBounds = true
            cell.bgView.layer.maskedCorners = [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]
        } else {
            cell.bgView.layer.cornerRadius = 0
        }
        cell.label.text = "Row \(indexPath.row)"
        return cell
    }
}