如何使用Core Data和iCloud在两台设备之间同步数据？

Question

我想要实现的是当用户创建,更改或删除数据时,persistent store它将与之同步,iCloud store然后更新登录到同一iCloud帐户的其他设备.

我创建了一个Core Data Stack使用Objective-C资源并尝试在Swift中编写自己的资源,但是我在使用登录到同一个iCloud帐户的两个设备同步数据时遇到问题.

例如,当iDevice A登录到iCloud时,它会将数据备份到iCloud,但是当iDevice B登录到iCloud时,应用程序会删除持久存储上已有的任何数据以保存iCloud备份,并且不会出现商店设备之间的任何更改在另一方面,但似乎保存到iCloud商店作为最新的备份,所以如果应用程序被删除并重新安装我看到其他设备做的最新备份 - 考虑到这一点,如果iDevice B已经登录,它除非重新安装应用程序并且最后一次备份是由其他设备完成的,否则不会使用来自iDevice A的数据.

有人知道在Core data stack使用相同的iCloud帐户在两台设备之间同步数据时我出错了吗？

核心数据堆栈:

// MARK: - Core Data stack
// All the following code is in my appDelgate Core data stack 

func observeCloudActions(persistentStoreCoordinator psc:      NSPersistentStoreCoordinator?) {
// Register iCloud notifications observers for;

//Stores Will change 
//Stores Did Change 
//persistentStoreDidImportUbiquitousContentChanges
//mergeChanges

}

//Functions for notifications

func mergeChanges(notification: NSNotification) {
NSLog("mergeChanges notif:\(notification)")
if let moc = managedObjectContext {
    moc.performBlock {
        moc.mergeChangesFromContextDidSaveNotification(notification)
        self.postRefetchDatabaseNotification()
    }
 }
}

  func persistentStoreDidImportUbiquitousContentChanges(notification: NSNotification) {
self.mergeChanges(notification);
 }    

func storesWillChange(notification: NSNotification) {
NSLog("storesWillChange notif:\(notification)");
if let moc = self.managedObjectContext {
    moc.performBlockAndWait {
        var error: NSError? = nil;
        if moc.hasChanges && !moc.save(&error) {
            NSLog("Save error: \(error)");
        } else {
            // drop any managed objects
        }
        moc.reset();
    }

       NSNotificationCenter.defaultCenter().postNotificationName("storeWillChange", object: nil)

 }
}

 func storesDidChange(notification: NSNotification) {
NSLog("storesDidChange posting notif");
self.postRefetchDatabaseNotification();
//Sends notification to view controllers to reload data      NSNotificationCenter.defaultCenter().postNotificationName("storeDidChange", object: nil)

 }

func postRefetchDatabaseNotification() {
dispatch_async(dispatch_get_main_queue(), { () -> Void in
          NSNotificationCenter.defaultCenter().postNotificationName("storeDidChange", object: nil)

 })
 }


// Core data stack 

lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "hyouuu.pendo" in the application's documents Application Support directory.
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as! NSURL
}()

lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("AppName", withExtension: "momd")!
NSLog("modelURL:\(modelURL)")
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
// The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)


let documentsDirectory = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as! NSURL


let storeURL = documentsDirectory.URLByAppendingPathComponent("CoreData.sqlite")

NSLog("storeURL:\(storeURL)")

let storeOptions = [NSPersistentStoreUbiquitousContentNameKey:"AppStore"]

var error: NSError? = nil
var failureReason = "There was an error creating or loading the application's saved data."

if coordinator!.addPersistentStoreWithType(
    NSSQLiteStoreType,
    configuration: nil,
    URL: storeURL,
    options: storeOptions,
    error: &error) == nil
{
    coordinator = nil
    // Report any error we got.
    let dict = NSMutableDictionary()
    dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
    dict[NSLocalizedFailureReasonErrorKey] = failureReason
    dict[NSUnderlyingErrorKey] = error
    error = NSError(domain: "Pendo_Error_Domain", code: 9999, userInfo: dict as [NSObject : AnyObject])
    // Replace this with code to handle the error appropriately.
    // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
    NSLog("AddPersistentStore error \(error), \(error!.userInfo)")
}

self.observeCloudActions(persistentStoreCoordinator: coordinator)

return coordinator
}()

lazy var managedObjectContext: NSManagedObjectContext? = {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
if coordinator == nil {
    return nil
}
var managedObjectContext = NSManagedObjectContext(concurrencyType: NSManagedObjectContextConcurrencyType.MainQueueConcurrencyType)
managedObjectContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()

Answer 1

这就是我的设置，它同步我的核心数据，并保持更改同步。

这是我的 AppDelegate 的。

    lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
    // Create the coordinator and store
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("APPNAME.sqlite")
    var error: NSError? = nil
    var failureReason = "There was an error creating or loading the application's saved data."
    // iCloud store
    var storeOptions = [NSPersistentStoreUbiquitousContentNameKey : "APPNAMEStore",NSMigratePersistentStoresAutomaticallyOption: true,
        NSInferMappingModelAutomaticallyOption: true]
    // iCloud storeOptions need to be added to the if statement
    do {
        try coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: NSURL.fileURLWithPath(url.path!), options: storeOptions)
    } catch var error1 as NSError {
        error = error1
        coordinator = nil
        // Report any error we got.
        var dict = [String: AnyObject]()
        dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
        dict[NSLocalizedFailureReasonErrorKey] = failureReason
        dict[NSUnderlyingErrorKey] = error
        error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
        // Replace this with code to handle the error appropriately.
        // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
        NSLog("Unresolved error \(error), \(error!.userInfo)")
        abort()
    } catch {
        fatalError()
    }

    return coordinator
}()

    // MARK: - iCloud
// This handles the updates to the data via iCLoud updates

func registerCoordinatorForStoreNotifications (coordinator : NSPersistentStoreCoordinator) {
    let nc : NSNotificationCenter = NSNotificationCenter.defaultCenter();

    nc.addObserver(self, selector: "handleStoresWillChange:",
        name: NSPersistentStoreCoordinatorStoresWillChangeNotification,
        object: coordinator)

    nc.addObserver(self, selector: "handleStoresDidChange:",
        name: NSPersistentStoreCoordinatorStoresDidChangeNotification,
        object: coordinator)

    nc.addObserver(self, selector: "handleStoresWillRemove:",
        name: NSPersistentStoreCoordinatorWillRemoveStoreNotification,
        object: coordinator)

    nc.addObserver(self, selector: "handleStoreChangedUbiquitousContent:",
        name: NSPersistentStoreDidImportUbiquitousContentChangesNotification,
        object: coordinator)
}