UISearchBar 在点击搜索文本字段时消失

Question

我创建了一个自定义的 tableView 标题，在其中我有一个 stackView 中的占位符视图，我想用 searchBar 替换它。这似乎有效，但是当我点击搜索栏时它消失了。我不确定问题是什么，我注意到当我拉动以刷新搜索栏时，它会显示并且处于活动状态。

自定义标题：

class FilterHeader: UIView {
    
    var searchPlaceHolderView: UIView = {
        let view = UIView(frame: .zero)
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = .lightGray
        return view
    }()
    
    let logButton: UIButton = {
        let button = UIButton(type: .system)
        button.backgroundColor = .white
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitle("Filter", for: .normal)
        button.titleLabel?.font = .systemFont(ofSize: 14, weight: .regular)
        button.setTitleColor(Colors.darkTextColor, for: .normal)
        
        let backgroundImage = UIImage(named: "icon_log",
                                      in: Bundle.frameworkBundle,
                                      compatibleWith: nil)
        button.setImage(backgroundImage, for: .normal)
        button.tintColor = .gray
        
        button.layer.cornerRadius = 6
        button.heightAnchor.constraint(equalToConstant: 40).isActive = true
        button.widthAnchor.constraint(equalToConstant: 80).isActive = true
        
        button.addTarget(self, action: #selector(didTapFilter(_:)), for: .touchUpInside)
        
        button.layer.borderColor = UIColor.lightGray.cgColor
        button.layer.borderWidth = 0.3
        
        button.titleEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 16)
        button.semanticContentAttribute = .forceRightToLeft
        
        
        return button
    }()
    
    let stackView: UIStackView = {
        let view = UIStackView()
        view.alignment = .center
        view.axis = .horizontal
        view.distribution = .fill
        view.spacing = 8
        view.translatesAutoresizingMaskIntoConstraints = false
        
        return view
    }()
    
    init() {
        super.init(frame: .zero)
        
        setupView()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func setupView() {
        
        backgroundColor = .red
        
        stackView.addArrangedSubview(searchPlaceHolderView)
        stackView.addArrangedSubview(logButton)
        
        addSubview(stackView)
        NSLayoutConstraint.activate([

            self.heightAnchor.constraint(equalToConstant: 100),

            stackView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 16),
            stackView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -16),
            stackView.centerYAnchor.constraint(equalTo: centerYAnchor, constant: -16)
        ])
    }
}

在 ViewController 上，我添加了这样的自定义标头：

    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        
        if section == 0 {
           
            let header = FilterHeader()
            let searchBar = searchController.searchBar
            searchBar.backgroundColor = .lightGray
            header.searchView.pinToSuperViewEdges(searchBar)
            return header
        }
        
        return nil
    }

    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        if section == 0 {
            return 100
        } else {
            return UITableView.automaticDimension
        }
        
    }

辅助函数

extension UIView {
    func pinToSuperViewEdges(_ view: UIView, insets: UIEdgeInsets = .zero) {
        view.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(view)
        NSLayoutConstraint.activate([
            self.leftAnchor.constraint(equalTo: view.leftAnchor, constant: insets.left),
            self.topAnchor.constraint(equalTo: view.topAnchor, constant: insets.top),
            self.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -insets.right),
            self.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -insets.bottom)
        ])
    }
}

我不确定我缺少什么以及导致搜索栏消失的原因。