如何将 UISearchController 与 SwiftUI 集成

问题描述

我有一个符合 UIViewControllerRepresentable 的 SearchController，并且我已经实现了所需的协议方法.但是，当我在 SwiftUI 结构中创建 SearchController 的实例时，SearchController 在加载后不会出现在屏幕上.有没有人对如何将 UISearchController 与 SwiftUI 集成有任何建议?谢谢！

I have a SearchController that conforms to UIViewControllerRepresentable, and I've implemented the required protocol methods. But when I created an instance of the SearchController in a SwiftUI struct, the SearchController doesn't appear on the screen once it's loaded. Does anyone have any suggestions on how I could integrate a UISearchController with SwiftUI? Thank you!

这是符合 UIViewControllerRepresentable 的 SearchController Struct:

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，它应该显示 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)
    }
}

这是一个没有出现在屏幕上的 SearchController 的图像:

推荐答案

(编辑)iOS 15:

iOS 15 添加了新属性 .searchable().你可能应该改用它.

(EDIT) iOS 15:

iOS 15 added the new property .searchable(). You should probably use that instead.

如果有人还在寻找，我制作了一个包来解决这个问题.

If anyone is still looking, I made a package to deal with this.

我还在此处为那些不喜欢链接或只想复制/粘贴的人提供了完整的相关源代码.

I'm also including the full relevant source code here for those who dislike links or just want to copy/paste.

扩展:

// Copyright © 2020 thislooksfun
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

import SwiftUI
import Combine

public extension View {
    public func navigationBarSearch(_ searchText: Binding<String>) -> some View {
        return overlay(SearchBar(text: searchText).frame(width: 0, height: 0))
    }
}

fileprivate struct SearchBar: UIViewControllerRepresentable {
    @Binding
    var text: String

    init(text: Binding<String>) {
        self._text = text
    }

    func makeUIViewController(context: Context) -> SearchBarWrapperController {
        return SearchBarWrapperController()
    }

    func updateUIViewController(_ controller: SearchBarWrapperController, context: Context) {
        controller.searchController = context.coordinator.searchController
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(text: $text)
    }

    class Coordinator: NSObject, UISearchResultsUpdating {
        @Binding
        var text: String
        let searchController: UISearchController

        private var subscription: AnyCancellable?

        init(text: Binding<String>) {
            self._text = text
            self.searchController = UISearchController(searchResultsController: nil)

            super.init()

            searchController.searchResultsUpdater = self
            searchController.hidesNavigationBarDuringPresentation = true
            searchController.obscuresBackgroundDuringPresentation = false

            self.searchController.searchBar.text = self.text
            self.subscription = self.text.publisher.sink { _ in
                self.searchController.searchBar.text = self.text
            }
        }

        deinit {
            self.subscription?.cancel()
        }

        func updateSearchResults(for searchController: UISearchController) {
            guard let text = searchController.searchBar.text else { return }
            self.text = text
        }
    }

    class SearchBarWrapperController: UIViewController {
        var searchController: UISearchController? {
            didSet {
                self.parent?.navigationItem.searchController = searchController
            }
        }

        override func viewWillAppear(_ animated: Bool) {
            self.parent?.navigationItem.searchController = searchController
        }
        override func viewDidAppear(_ animated: Bool) {
            self.parent?.navigationItem.searchController = searchController
        }
    }
}

用法:

import SwiftlySearch

struct MRE: View {
  let items: [String]

  @State
  var searchText = ""

  var body: some View {
    NavigationView {
      List(items.filter { $0.localizedStandardContains(searchText) }) { item in
        Text(item)
      }.navigationBarSearch(self.$searchText)
    }
  }
}

这篇关于如何将 UISearchController 与 SwiftUI 集成的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！