iOS ICloud 核心数据从应用程序打开关闭

Question

在我的 iOS 应用程序中，我已将我的数据库设置为与 iCloud 同步。当我插入一条新记录时，数据会正确更新，我可以在我的容器文件夹中观看它。 现在我想设置一个开关，让用户在应用程序运行时启用或禁用与 iCloud 的核心数据同步过程，但我不知道该怎么做。

我是 iOS 和 ICloud 的新手。请需要帮助。提前致谢。

这是我在 AppDelegate 中的代码:

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"myStore.sqlite"];    
    NSURL *cloudRootURL=[fileManager URLForUbiquityContainerIdentifier:nil];

    NSString *pathToCloudFile = [[cloudRootURL path]stringByAppendingPathComponent:@"Documents"];
    pathToCloudFile = [pathToCloudFile stringByAppendingPathComponent:@"myCloudLogs"];

    NSURL *cloudURL = [NSURL fileURLWithPath:pathToCloudFile];

    NSString *cloudStoreTitle = @"myStoreCloud";
    NSDictionary *options = @{NSMigratePersistentStoresAutomaticallyOption : @YES,
                          NSInferMappingModelAutomaticallyOption : @YES,
                          NSPersistentStoreUbiquitousContentURLKey: cloudURL,
                          NSPersistentStoreUbiquitousContentNameKey: cloudStoreTitle};

    NSError *error = nil;
    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];


   if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]) {

       //Replace this implementation 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.

       //Typical reasons for an error here include:
       // The persistent store is not accessible;
       // The schema for the persistent store is incompatible with current managed object model.
       //Check the error message to determine what the actual problem was.


       //If the persistent store is not accessible, there is typically something wrong with the file path. Often, a file URL is pointing into the application's resources directory instead of a writeable directory.

       //If you encounter schema incompatibility errors during development, you can reduce their frequency by:
       // Simply deleting the existing store:
       //[[NSFileManager defaultManager] removeItemAtURL:storeURL error:nil]

       // Performing automatic lightweight migration by passing the following dictionary as the options parameter:
       //@{NSMigratePersistentStoresAutomaticallyOption:@YES, NSInferMappingModelAutomaticallyOption:@YES}

       //Lightweight migration will only work for a limited set of schema changes; consult "Core Data Model Versioning and Data Migration Programming Guide" for details.


       NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
       abort();
   }

   NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];

   [notificationCenter addObserver:self
                       selector:@selector(processStoresWillChange:)
                           name:NSPersistentStoreCoordinatorStoresWillChangeNotification
                         object:_persistentStoreCoordinator];

   [notificationCenter addObserver:self
                       selector:@selector(processStoresDidChange:)
                           name:NSPersistentStoreCoordinatorStoresDidChangeNotification
                         object:_persistentStoreCoordinator];

   [notificationCenter addObserver:self
                       selector:@selector(processContentChanges:)
                           name:NSPersistentStoreDidImportUbiquitousContentChangesNotification
                         object:_persistentStoreCoordinator];


   return _persistentStoreCoordinator;
}

Answer 1

不要使用无处不在的容器。查看苹果文档以从 icloud 同步中排除文件。 https://developer.apple.com/library/ios/qa/qa1719/_index.html如果将 bool 值设置为 NO。该文件将再次包含在要备份的文件中。在文档中创建核心数据(数据库)以使其自动同步。使用此代码，您可以随时通过单击按钮以编程方式禁用同步。但请注意，如果数据库大小增长太多，应用程序可能会被拒绝，因为只有“用户数据”应该与 icloud 同步。