我正在寻找一种使用MVVM（放弃@FetchRequest）来使用CoreData对象的方法。经过试验，我得到了以下实现：
软件包URL：https://github.com/TimmysApp/DataStruct
Datable.swift:

protocol Datable {
    associatedtype Object: NSManagedObject
//MARK: - Mapping
    static func map(from object: Object) -> Self
    func map(from object: Object) -> Self
//MARK: - Entity
    var object: Object {get}
//MARK: - Fetching
    static var modelData: ModelData<Self> {get}
//MARK: - Writing
    func save()
}

extension Datable {
    static var modelData: ModelData<Self> {
        return ModelData()
    }
    func map(from object: Object) -> Self {
        return Self.map(from: object)
    }
    func save() {
        _ = object
        let viewContext = PersistenceController.shared.container.viewContext
        do {
            try viewContext.save()
        }catch {
            print(String(describing: error))
        }
    }
}

extension Array {
    func model<T: Datable>() -> [T] {
        return self.map({T.map(from: $0 as! T.Object)})
    }
}

ModelData.swift:

class ModelData<T: Datable>: NSObject, ObservableObject, NSFetchedResultsControllerDelegate {
    var publishedData = CurrentValueSubject<[T], Never>([])
    private let fetchController: NSFetchedResultsController<NSFetchRequestResult>
    override init() {
        let fetchRequest = T.Object.fetchRequest()
        fetchRequest.sortDescriptors = []
        fetchController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: PersistenceController.shared.container.viewContext, sectionNameKeyPath: nil, cacheName: nil)
        super.init()
        fetchController.delegate = self
        do {
            try fetchController.performFetch()
            publishedData.value = (fetchController.fetchedObjects as? [T.Object] ?? []).model()
        }catch {
            print(String(describing: error))
        }
    }
    func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        guard let data = controller.fetchedObjects as? [T.Object] else {return}
        self.publishedData.value = data.model()
    }
}

Attempt.swift:

struct Attempt: Identifiable, Hashable {
    var id: UUID?
    var password: String
    var timestamp: Date
    var image: Data?
}

//MARK: - Datable
extension Attempt: Datable {
    var object: AttemptData {
        let viewContext = PersistenceController.shared.container.viewContext
        let newAttemptData = AttemptData(context: viewContext)
        newAttemptData.password = password
        newAttemptData.timestamp = timestamp
        newAttemptData.image = image
        return newAttemptData
    }
    static func map(from object: AttemptData) -> Attempt {
        return Attempt(id: object.aid ?? UUID(), password: object.password ?? "", timestamp: object.timestamp ?? Date(), image: object.image)
    }
}

ViewModel.swift:

class HomeViewModel: BaseViewModel {
    @Published var attempts = [Attempt]()
    required init() {
        super.init()
        Attempt.modelData.publishedData.eraseToAnyPublisher()
            .sink { [weak self] attempts in
                self?.attempts = attempts
            }.store(in: &cancellables)
    }
}

到目前为止，这是工作像一个魅力，但我想检查这是否是最好的方式来做，并改善它，如果可能的话。请注意，我已经使用@FetchRequest与SwiftUI超过一年了，现在决定转移到MVVM，因为我正在使用它在我所有的Storyboard项目。