Mac Catalyst 的 UIDocumentPickerViewController 配置答案

【问题标题】：UIDocumentPickerViewController configuration for Mac CatalystMac Catalyst 的 UIDocumentPickerViewController 配置
【发布时间】：2021-09-10 16:13:14
【问题描述】：

在 Mac Catalyst 中使用 UIDocumentPickerViewController 时，是否需要额外的功能、权限或沙盒配置？我错过了一个警告吗？

在使用Catalyst上运行以下代码（11.4），在选择文件时，切勿调用didPickDocumentsAt:委托函数。但是，如果选择器被关闭或尝试打开文件，则会调用 documentPickerWasCancelled。

我最初怀疑由于 SwiftUI 的 View 结构重新创建不正确的内容类型或委托解除分配，但当调用 as cancel 时，我怀疑不是。

需要注意的是，在为 macOS 配置 UIDocumentPickerViewController 而为 iOS 配置 true 时，asCopy 必须是 false。

该错误表示沙盒权限错误：

DocumentPickerSwiftUI[42570:1472986] Failed to create an FPSandboxingURLWrapper for file:///Users/ed/test_file.txt. Error: Error Domain=NSPOSIXErrorDomain Code=1 "couldn't issue sandbox extension com.apple.app-sandbox.read-write for '/Users/ed/test_file.txt': Operation not permitted" UserInfo={NSDescription=couldn't issue sandbox extension com.apple.app-sandbox.read-write for '/Users/ed/test_file.txt': Operation not permitted}

当前能力配置（用户选择文件的只读访问）：

import SwiftUI
import UIKit
import UniformTypeIdentifiers

struct ContentView: View {
    @State var showDocumentPicker: Bool = false

    var body: some View {
        documentPickerButton
    }

    private var documentPickerButton: some View {
        Button(action: {
            showDocumentPicker.toggle()
        }, label: {
            Text("Open")
        })
        .sheet(isPresented: self.$showDocumentPicker) {
            AudioFilePicker()
        }
    }
}

final class AudioFilePicker: UIViewControllerRepresentable {

    var viewController = UIDocumentPickerViewController(forOpeningContentTypes: [.item], asCopy: false)

    class Coordinator: NSObject, UIDocumentPickerDelegate {

        var parent: AudioFilePicker

        init(parent: AudioFilePicker) {
            self.parent = parent
        }

        func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
            print("Picker Loaded: \(String(describing: urls.first?.absoluteString))")
            // Do something with URL (never called)
        }

        func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
            print("Picker Cancelled")
        }
    }

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

    func makeUIViewController(context: Context) -> UIDocumentPickerViewController {
        viewController.delegate = context.coordinator
        return viewController
    }

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

【问题讨论】：

标签： macos swiftui appstore-sandbox mac-catalyst uidocumentpickerviewcontroller

【解决方案1】：

该错误确实表示权限错误。尝试添加：

<key>com.apple.security.files.user-selected.read-write</key>
<true/>

【讨论】：