从目标C到SWIFT-以前的核心数据内容未加载

Question

我正在尝试迁移我的应用程序，该应用程序使用目标C现在使用Swift。我没有错误，但没有在应用程序中加载信息。我已经将旧模型导入了新应用程序中的新项目

核心数据存储

init(inMemory: Bool = false) {
    container = NSPersistentCloudKitContainer(name: "Medicine_Tracker")
    if inMemory {
        container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
    }
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    container.viewContext.automaticallyMergesChangesFromParent = true
}

中，并使用以下内容在视图中加载了 。 NSLOG结果计数：0，而应该为项目计数：2

struct MedicineView: View {

@Environment(\.managedObjectContext) private var viewContext

@FetchRequest(
    sortDescriptors: [NSSortDescriptor(keyPath: \Medicine.name, ascending: true)],
    animation: .default)
private var items: FetchedResults<Medicine>

var body: some View {
    NavigationView {
        List {
            ForEach(items) { item in
                NavigationLink(destination: MedicineDetailView(medicine: item)) {
                    Text("\(item.name ?? "Error")")
                }
            }
        }
        .navigationBarTitle("Medicines", displayMode: .inline)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                NavigationLink(destination: MedicineAddView()) {
                    Label("Add Item", systemImage: "plus")
                }
            }
        }
        .onAppear() {
            NSLog("Item Count: \(items.count)")
        }
    }
}

}

，旧应用程序使用

- (NSManagedObjectModel *)managedObjectModel
{
    if (__managedObjectModel != nil) {
        return __managedObjectModel;
    }
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"Medicine_Tracker" withExtension:@"momd"];
    __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    
    return __managedObjectModel;
}

// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (__persistentStoreCoordinator != nil) {
        return __persistentStoreCoordinator;
    }
    
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Medicine_Tracker.sqlite"];
    
    NSError *error = nil;
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
                             [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
    
    if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]) {
        
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    }
    
    return __persistentStoreCoordinator;
}