ios - 如何从 SwiftUI 调用 PHPhotoLibrary presentLimitedLibraryPicker？

Question

从 SwiftUI 调用 PHPhotoLibrary 的 presentLimitedLibraryPicker 方法的正确方法是什么？
该方法需要一个 UIViewController，而我在 SwiftUI 中没有。
我尝试使用 UIViewControllerRepresentable 来创建 UIViewController，它可以工作，但结果是出现了两个 View Controller ，一个是我使用 UIViewControllerRepresentable 创建的，一个是有限库选择器。
两个 View Controller 都需要关闭才能到达原始屏幕，这是不可取的。
总结一下我看到的问题:

presentLimitedLibraryPicker 通过传递 ViewController 来工作。

这让我创建并呈现了一个虚拟 ViewController，这样我就可以调用该方法。

无法获得对有限库选择器的引用，它也不提供委托(delegate)。所以我无法检测到 Limited Library Picker Controller 何时被解除。

这是我的尝试(它显示了选择器，但是当您关闭它时，您也需要关闭额外的虚拟 View Controller :

import Foundation
import SwiftUI
import Photos
import PhotosUI

struct TestView: View {

   @State var showLibraryPicker = false

var body: some View {
    NavigationView {
        VStack {
            Button("Open Library Picker") { showLibraryPicker = true }
        }
        .navigationBarTitle("Test", displayMode: .inline)
        .navigationViewStyle(StackNavigationViewStyle())
        .sheet(isPresented: $showLibraryPicker, onDismiss: { print("Dismissed") }) {
            TestLimitedLibraryPicker()
            }
        }
    }
}


struct TestLimitedLibraryPicker: UIViewControllerRepresentable {

     func makeUIViewController(context: Context) -> UIViewController {
         let controller = UIViewController()
         PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: controller)
          return controller
     }

    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {

     }
}

Answer 1

这是一些演示方法。使用 Xcode 12/iOS 14 准备和测试。

struct TestPhotosView: View {

    @State var showLibraryPicker = false

    var body: some View {
        NavigationView {
            VStack {
                Button("Open Library Picker") { self.showLibraryPicker = true }
            }
            .navigationBarTitle("Test", displayMode: .inline)
            .navigationViewStyle(StackNavigationViewStyle())
            .background(Group {
                if self.showLibraryPicker {
                    TestLimitedLibraryPicker(isPresented: $showLibraryPicker)
                }
            })
        }
    }
}


struct TestLimitedLibraryPicker: UIViewControllerRepresentable {
    @Binding var isPresented: Bool

    func makeUIViewController(context: Context) -> UIViewController {
        let controller = UIViewController()

        DispatchQueue.main.async {
            PHPhotoLibrary.requestAuthorization() { result in
                PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: controller)
                context.coordinator.trackCompletion(in: controller)
            }
        }
        
        return controller
    }

    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}

    func makeCoordinator() -> Coordinator {
        Coordinator(isPresented: $isPresented)
    }
    class Coordinator: NSObject {
        private var isPresented: Binding<Bool>
        init(isPresented: Binding<Bool>) {
            self.isPresented = isPresented
        }

        func trackCompletion(in controller: UIViewController) {
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self, weak controller] in
                if controller?.presentedViewController == nil {
                    self?.isPresented.wrappedValue = false
                } else if let controller = controller {
                    self?.trackCompletion(in: controller)
                }
            }
        }
    }
}