为 SwiftUI macOS 应用程序使用 @fetchRequest(entity:) 崩溃

Question

我正在尝试使用 Core Data 为 macOS 运行一个基本的测试 SwiftUI 应用程序，但我遇到了一个问题。当我在我看来使用它时：

@FetchRequest(entity: Note.entity(), sortDescriptors: []) let notes: FetchedResults<Note>

该应用程序崩溃并出现以下错误：

NoteTaker [error] error: No NSEntityDescriptions in any model claim the NSManagedObject subclass 'NoteTaker.Note' so +entity is confused.  Have you loaded your NSManagedObjectModel yet ?
CoreData: error: No NSEntityDescriptions in any model claim the NSManagedObject subclass 'NoteTaker.Note' so +entity is confused.  Have you loaded your NSManagedObjectModel yet ?

NoteTaker [error] error: +[NoteTaker.Note entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass
CoreData: error: +[NoteTaker.Note entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass

NoteTaker executeFetchRequest:error: A fetch request must have an entity.

现在，如果我使用 FetchRequest 的替代形式，那么它就可以正常工作，尽管代码要丑得多：

// outside of the view
func getAllNotes() -> NSFetchRequest<Note> {
  let request: NSFetchRequest<Note> = Note.fetchRequest()
  request.sortDescriptors = []
  return request
}

// in the view
@FetchRequest(fetchRequest: getAllNotes()) var notes: FetchedResults<Note>

另外，如果我把它变成一个 iOS 应用程序，那么 @FetchRequest 的实体版本就可以正常工作。

有任何想法吗？

Answer 1

使用Storyboard 模板，然后在视图控制器中使用 SwiftUI 设置视图。

override func viewWillAppear() {
        super.viewWillAppear()

        let context = (NSApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        let contentView = ContentView().environment(\.managedObjectContext, context)

        view = NSHostingView(rootView: contentView)
    }