SwiftUI文档应用中NSWorkspace.open启动TextEdit.app失败问题排查

在基于文档的SwiftUI macOS应用里，尝试调用NSWorkspace.open(_:withApplicationAt:configuration:completionHandler:)将当前编辑的Test.exampletext文件打开到TextEdit，但执行失败，错误提示为：

The application “TextEdit.app” could not be launched because a miscellaneous error occurred.

已确认以下信息：

• 文件确实存在
• TextEdit的路径正确
• 当前应用运行时，手动可在TextEdit中打开该文件

通过FocusedValueKey获取文档URL的功能正常，猜测失败原因可能为：

• 沙箱与访问权限问题
• NSWorkspace.OpenConfiguration配置有误
• 文件被当前应用锁定，导致TextEdit无法打开

用户核心实现代码：

func openFile(with url: URL) {
    guard 
      let texteditURL = URL(string: "/System/Applications/TextEdit.app"),
      FileManager.default.fileExists(atPath: texteditURL.absoluteString)
    else {
      AppLogger.standard.debug("Could not get url for app TextEdit.")
      return
    }
    let configuration = NSWorkspace.OpenConfiguration()
    configuration.activates = true
    configuration.allowsRunningApplicationSubstitution = true
    configuration.hidesOthers = true
    configuration.promptsUserIfNeeded = true
    NSWorkspace.shared.open(
      [url],
      withApplicationAt: texteditURL,
      configuration: configuration
    ) { _, error in
        if let error {
          AppLogger.standard.error("\(error.localizedDescription)")
        }
    }
}

完整代码：

import OSLog
import SwiftUI
import UniformTypeIdentifiers

//MARK: App entry point
@main
struct poc_UrlOfOpenedDocumentApp: App {
  var body: some Scene {
    DocumentGroup(newDocument: poc_UrlOfOpenedDocumentDocument()) { file in
      ContentView(document: file.$document)
        .focusedSceneValue(
          \.fileURL,
           {
             if let url = file.fileURL {
               AppLogger.standard.debug("File url at app start is: \(url.description)")
               return Binding { url } set: { _ in }
             }
             AppLogger.standard.warning("URL is unknown …")
             return nil
           }()
        )
    }
  }
}

//MARK: Content View
struct ContentView: View {
  @FocusedValue(\.fileURL) var fileUrl
  @Binding var document: poc_UrlOfOpenedDocumentDocument

  var body: some View {
    TextEditor(text: $document.text)
    Text(fileUrl?.wrappedValue.debugDescription ?? "n/a")
      .onAppear {
        AppLogger.standard.debug("URL is (onAppear): \(fileUrl?.wrappedValue.description ?? "n/a")")
      }
    Button("Open in TextEdit") {
      guard let fileUrl
      else {
        AppLogger.standard.warning("There is currently no file url.")
        return
      }
      AppLogger.standard.debug("URL is (Button): \(fileUrl.wrappedValue.absoluteString)")
      openFile(with: fileUrl.wrappedValue)
    }
    .padding(.bottom)
  }

  //MARK: **** Open file logic ****
  func openFile(with url: URL) {
    guard 
      let texteditURL = URL(string: "/System/Applications/TextEdit.app"),
      FileManager.default.fileExists(atPath: texteditURL.absoluteString)
    else {
      AppLogger.standard.debug("Could not get url for app TextEdit.")
      return
    }
    let configuration = NSWorkspace.OpenConfiguration()
    configuration.activates = true
    configuration.allowsRunningApplicationSubstitution = true
    configuration.hidesOthers = true
    configuration.promptsUserIfNeeded = true
    NSWorkspace.shared.open(
      [url],
      withApplicationAt: texteditURL,
      configuration: configuration
    ) { _, error in
        if let error {
          AppLogger.standard.error("\(error.localizedDescription)")
        }
    }
  }
}

//MARK: Preview
#Preview {
  ContentView(document: .constant(poc_UrlOfOpenedDocumentDocument()))
}

//MARK: FocuseValues definition
extension FocusedValues {
  struct DocumentFocusedValues: FocusedValueKey {
    typealias Value = Binding<URL>
  }

  var fileURL: Binding<URL>? {
    get {
      self[DocumentFocusedValues.self]
    }
    set {
      self[DocumentFocusedValues.self] = newValue
    }
  }
}

//MARK: AppLogger
enum AppLogger {
  private static let bundleID = Bundle.main.bundleIdentifier

  static let standard = Logger(subsystem: bundleID  ?? "", category: "default")
}

//MARK: Document definitions
extension UTType {
  static var exampleText: UTType {
    UTType(importedAs: "com.example.plain-text")
  }
}

struct poc_UrlOfOpenedDocumentDocument: FileDocument {
  var text: String
  var fileURL: URL?

  init(
    text: String = "Hello, world!"
  ) {
    self.text = text
  }

  static var readableContentTypes: [UTType] { [.exampleText] }

  init(configuration: ReadConfiguration) throws {
    guard let data = configuration.file.regularFileContents,
          let string = String(data: data, encoding: .utf8)
    else {
      throw CocoaError(.fileReadCorruptFile)
    }
    text = string
  }

  func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
    let data = text.data(using: .utf8)!
    return .init(regularFileWithContents: data)
  }
}

1. 修复TextEdit URL的创建与验证逻辑 #

核心错误在于本地文件路径的URL创建方式和文件存在性校验的参数错误：

• 用URL(string:)创建本地应用路径会生成带file://前缀的URL，而FileManager.default.fileExists(atPath:)需要传入纯路径字符串（不带前缀）
• 正确的本地文件URL创建方式是URL(fileURLWithPath:)

修改后的代码：

func openFile(with url: URL) {
    let texteditURL = URL(fileURLWithPath: "/System/Applications/TextEdit.app")
    guard FileManager.default.fileExists(atPath: texteditURL.path) else {
        AppLogger.standard.debug("Could not get url for app TextEdit.")
        return
    }
    // 后续逻辑...
}

2. 简化OpenConfiguration配置 #

移除不必要的配置项，先保证基础功能正常：

let configuration = NSWorkspace.OpenConfiguration()
configuration.activates = true // 激活目标应用
configuration.promptsUserIfNeeded = true // 必要时提示用户授权

3. 检查沙箱权限 #

如果应用开启了沙箱：

• 在Signing & Capabilities中确保添加Outgoing Connections (Client)权限
• 确认User Selected File权限设置为Read/Write（文档应用默认会配置，但需检查）

4. 适配Deckset应用的替代方案 #

如果实际需求是打开到Deckset，可通过Bundle ID查找应用URL，避免硬编码路径：

func openInDeckset(with url: URL) {
    guard let decksetURL = NSWorkspace.shared.urlForApplication(withBundleIdentifier: "com.unsignedinteger.Deckset") else {
        AppLogger.standard.debug("Deckset app not found.")
        return
    }
    let configuration = NSWorkspace.OpenConfiguration()
    configuration.activates = true
    
    NSWorkspace.shared.open([url], withApplicationAt: decksetURL, configuration: configuration) { _, error in
        if let error {
            AppLogger.standard.error("\(error.localizedDescription)")
        }
    }
}

内容的提问来源于stack exchange，提问作者appfrosch