如何将UISearchController与SwiftUI集成

Question

我有一个符合UIViewControllerRepresentable的SearchController，并且已经实现了必需的协议方法。但是，当我在SwiftUI结构中创建SearchController的实例时，一旦加载，SearchController不会出现在屏幕上。有人对我如何将UISearchController与SwiftUI集成有任何建议吗？谢谢！

这是符合UIViewControllerRepresentable的SearchController结构：

struct SearchController: UIViewControllerRepresentable {

    let placeholder: String
    @Binding var text: String

    func makeCoordinator() -> Coordinator {
        return Coordinator(self)
    }

    func makeUIViewController(context: Context) -> UISearchController {
        let controller = UISearchController(searchResultsController: nil)
        controller.searchResultsUpdater = context.coordinator
        controller.obscuresBackgroundDuringPresentation = false
        controller.hidesNavigationBarDuringPresentation = false
        controller.searchBar.delegate = context.coordinator
        controller.searchBar.placeholder = placeholder

        return controller
    }

    func updateUIViewController(_ uiViewController: UISearchController, context: Context) {
        uiViewController.searchBar.text = text
    }

    class Coordinator: NSObject, UISearchResultsUpdating, UISearchBarDelegate {

        var controller: SearchController

        init(_ controller: SearchController) {
            self.controller = controller
        }

        func updateSearchResults(for searchController: UISearchController) {
            let searchBar = searchController.searchBar
            controller.text = searchBar.text!
        }
    }
}

这是我的SwiftUIView的代码，应显示SearchController：

struct SearchCarsView: View {

    let cars = cardsData

    // MARK: @State Properties

    @State private var searchCarsText: String = ""

    // MARK: Views

    var body: some View {
        SearchController(placeholder: "Name, Model, Year", text: $searchCarsText)
           .background(Color.blue)
    }
}

这是SearchController的图像未出现在屏幕上：

enter image description here

Answer 1

在这种情况下，实际视觉元素是UISearchBar，因此最简单的起点应如下

import SwiftUI
import UIKit

struct SearchView: UIViewRepresentable {
    let controller = UISearchController()
    func makeUIView(context: UIViewRepresentableContext<SearchView>) -> UISearchBar {
        self.controller.searchBar
    }

    func updateUIView(_ uiView: UISearchBar, context: UIViewRepresentableContext<SearchView>) {

    }

    typealias UIViewType = UISearchBar


}

struct TestSearchController: View {
    var body: some View {
        SearchView()
    }
}

struct TestSearchController_Previews: PreviewProvider {
    static var previews: some View {
        TestSearchController()
    }
}

接下来的所有操作都可以像往常一样在init中进行配置，并作为委托进行协调。

Answer 2

我曾尝试使UISearchController与NavigationView和UIViewRepresentable配合使用以注入搜索控制器，但结果确实有问题。可能最好的方法是使用常规的UINavigationController而不是NavigationView，然后再使用容器UIViewController，在其中将NavigationItem.searchController设置为UISearchController。