如何为 CoreData 数据库切换 iCloud 同步？

Question

我想要允许打开和关闭 CoreData 数据库的iCloud 同步。当用户切换设置时，调用

updateContainer()

。如果应用程序在启用 iCould 同步的情况下启动，则同步有效。但是在 iCould 关闭并重新打开后，同步不起作用。

在控制台的垃圾 CloudKit 日志中，我发现了两个可疑警告：

CloudKit setup failed because there is another instance of this persistent store actively syncing with CloudKit in this process.

和

Told to tear down with reason: Error NSCocoaErrorDomain:134410

有人有过如何实现这一点的经验并且知道这里出了什么问题吗？

这是我的

PersistenceController.swift

import CoreData

class PersistenceController {
    static var shared = PersistenceController()
    
    lazy var container: NSPersistentContainer = {
        setupPersistentContainer()
    }()
    
    func updateContainer() {
        saveContext()
        container = setupPersistentContainer()
    }
    
    func saveContext() {...}
    
    private func setupPersistentContainer() -> NSPersistentContainer {
        // this value is synchronised across devices via NSUbiquitousKeyValueStore in iCloud
        let iCloudSyncEnabled = UserDefaults.standard.bool(forKey: iCouldSyncKey)
        
        var persistentContainer = getPersistentContainer(iCloudSync: iCloudSyncEnabled)
        
        guard let description = persistentContainer.persistentStoreDescriptions.first else {
            fatalError("Could not get persistentStoreDescription")
        }
        
        // Set merge policy
        persistentContainer.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
        
        // Enable HistoryTracking: This allows a non-iCloud persistent container to keep track of changes if a user changes their mind and turns it on.
        description.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
        
        if iCloudSyncEnabled {
            persistentContainer.viewContext.automaticallyMergesChangesFromParent = true
            description.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
        }
        
        persistentContainer.loadPersistentStores { storeDescription, error in
            if let error = error as NSError? {
                fatalError("Unresolved error \(error)")
            }
        }
        
        return persistentContainer
    }
    
    private func getPersistentContainer(iCloudSync iCloudSyncEnabled: Bool) -> NSPersistentContainer {
        let modelName = "Model"
        if iCloudSyncEnabled {
            print("Using NSPersistentCloudKitContainer")
            return NSPersistentCloudKitContainer(name: modelName)
        } else {
            print("Using NSPersistentContainer")
            return NSPersistentContainer(name: modelName)
            
        }
     }
}

此方法部分基于CoreData+CloudKit |打开/关闭 iCloud 同步切换