如何修复 didSelectRowAt 返回的错误 indexPath？

Posted 2023-03-11

【中文标题】如何修复 didSelectRowAt 返回的错误 indexPath？

【英文标题】：How to fix wrong indexPath returned by didSelectRowAt?

【发布时间】：2019-11-08 03:56:18

【问题描述】：

我有一个 UITableView；没有 tableHeaderView 点击一行并触发 didSelectRowAt 返回正确的索引路径。

当我设置 tableHeaderView 属性时，didSelectRowAt 要么不触发，要么返回 tappedRow + 2。我哪里出错了？

这是我的代码

class MenuController: UIViewController 
    // Mark -- Properties
    var tableView: UITableView!
    var delegate: HomeControllerDelegate?
    var headerView: HeaderView? = nil
    var user: User? = nil

    // Mark -- Init

    override func viewDidLoad() 
        super.viewDidLoad()
        configureTableView()
        if let user = self.user 
            populateMenuHeader(email: user.email, firstName: user.firstName, lastName: user.lastName, imageUrl: user.imageUrl)
        
    

    override func viewWillLayoutSubviews() 
        super.viewWillLayoutSubviews()
        //updateHeaderViewHeight(for: tableView.tableHeaderView)
    

    func updateHeaderViewHeight(for header: UIView?) 
        guard let headerView = headerView else  return 
        headerView.frame.size.height = 170
    

    func populateMenuHeader(email: String, firstName: String, lastName: String, imageUrl: String) 
        headerView?.emailLabel?.text = email
        headerView?.nameLabel?.text = "\(firstName) \(lastName)"
        let request = ImageRequest(
            url: URL(string: imageUrl)!,
            processors: [
                ImageProcessor.Resize(size: CGSize(width: 70, height: 70)),
                ImageProcessor.Circle()
            ]
        )
        Nuke.loadImage(with: request, into: headerView!.imageView!)
    

    // Mark -- Handlers
    func configureTableView() 
        // Create Material Header
        headerView = HeaderView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 170))
        //headerView?.heightAnchor.constraint(equalToConstant: 170).isActive = true
        headerView?.translatesAutoresizingMaskIntoConstraints = false

        tableView = UITableView()
        tableView.delegate = self
        tableView.dataSource = self

        tableView.tableHeaderView = headerView
        tableView.sectionHeaderHeight = 170

        tableView.register(MenuOptionCell.self, forCellReuseIdentifier: reuseIdentifier)
        tableView.backgroundColor = .darkGray
        tableView.separatorStyle = .none
        tableView.rowHeight = 80

        view.addSubview(tableView)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
    


extension MenuController: UITableViewDelegate, UITableViewDataSource 
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
        return 5
    

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
        let cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifier, for: indexPath) as! MenuOptionCell
        let menuOption = MenuOption(rawValue: indexPath.row)
        cell.descriptionLabel.text = menuOption?.description
        cell.iconImageView.image = menuOption?.image
        return cell
    

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 
        let row = indexPath.row
        print("tapped row: \(row)")
        let menuOption = MenuOption(rawValue: row)
        delegate?.handleMenuToggle(forMenuOption: menuOption)
    


class CustomView: UIView 
    override func draw(_ rect: CGRect) 
        super.draw(rect)

        if let context = UIGraphicsGetCurrentContext() 
            context.setStrokeColor(UIColor.white.cgColor)
            context.setLineWidth(1)
            context.move(to: CGPoint(x: 0, y: bounds.height))
            context.addLine(to: CGPoint(x: bounds.width, y: bounds.height))
            context.strokePath()
        
    


class HeaderView : UIView 
    var imageView: UIImageView? = nil
    var nameLabel: UILabel? = nil
    var emailLabel: UILabel? = nil

    override init(frame: CGRect) 
        super.init(frame: frame)
        imageView = UIImageView()
        imageView?.translatesAutoresizingMaskIntoConstraints = false
        nameLabel = UILabel()
        nameLabel?.translatesAutoresizingMaskIntoConstraints = false
        nameLabel?.font = UIFont(name: "Avenir-Light", size: 20)
        nameLabel?.text = "Test name"
        nameLabel?.textColor = .white
        emailLabel = UILabel()
        emailLabel?.translatesAutoresizingMaskIntoConstraints = false
        emailLabel?.textColor = .white
        emailLabel?.font = UIFont(name: "Avenir-Light", size: 15)
        emailLabel?.text = "[e-mail]"
        self.addSubview(imageView!)
        self.addSubview(nameLabel!)
        self.addSubview(emailLabel!)
        let lineView = CustomView(frame: CGRect(x: 0, y: frame.height - 1, width: frame.width, height: 1))
        self.addSubview(lineView)


        imageView?.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20).isActive = true
        imageView?.topAnchor.constraint(equalTo: topAnchor, constant: 20).isActive = true
        imageView?.widthAnchor.constraint(equalTo: widthAnchor, constant: 70).isActive = true
        imageView?.heightAnchor.constraint(equalTo: heightAnchor, constant: 70).isActive = true

        nameLabel?.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20).isActive = true
        nameLabel?.topAnchor.constraint(equalTo: imageView!.bottomAnchor, constant: 10).isActive = true

        emailLabel?.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20).isActive = true
        emailLabel?.topAnchor.constraint(equalTo: nameLabel!.bottomAnchor, constant: 5).isActive = true
    

    required init?(coder aDecoder: NSCoder) 
          fatalError("init(coder:) has not been implemented")
    

【参考方案1】：

问题似乎是由于您没有正确设置标题视图的高度。 tableHeaderView 的文档指出：

将视图分配给此属性时，将该视图的高度设置为非零值。表格视图只考虑视图框架矩形的高度；它会自动调整标题视图的宽度以匹配表格视图的宽度。

更新您的标题视图代码：

变化：

headerView = HeaderView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 170))
//headerView?.heightAnchor.constraint(equalToConstant: 170).isActive = true
headerView?.translatesAutoresizingMaskIntoConstraints = false

...

tableView.sectionHeaderHeight = 170

只是：

headerView = HeaderView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 170))

就是这样。无需弄乱约束。无需设置无关的部分高度。只需为标题视图的框架指定所需的高度即可。

【讨论】：

谢谢！禁用自动布局修复行点击。但现在我的 HeaderView 显示非常不稳定。为什么启用自动布局可以解决行敲击问题？我希望 tableView 能够正确地将点击与 indexPath 匹配，并且仅使用高度为 170 的 CGRect 初始化 headerView。

您的评论自相矛盾。首先你说禁用自动布局可以修复行点击，然后你问为什么启用它可以解决问题。

抱歉！为什么启用***自动布局可以解决行敲击问题？

但未启用自动布局。解决方法是（正确地）依赖提供的框架。当您执行translatesAutoresizingMaskIntoConstraints = false 时，您是在告诉自动布局忽略视图的框架并依赖约束。

知道了。我误解了一些基本的东西。要去打文档。感谢您的指导！