Question

我正在尝试学习如何将iCloud与coredata一起使用。我的目标是在mac / ios上同步一个数据库文件。我的mac和iOS应用程序似乎都在更新iCloud，因为我可以在System Preferences-＆gt; iCloud-＆gt; Manage ...中看到它...有一个名为Unknown的应用程序，每当我在ios / mac应用程序上更改某些内容时会变得越来越大大。这让我觉得应用程序正在存储对云的更改。问题是，当我在另一个平台上更改内容时，我没有得到NSPersistentStoreDidImportUbiquitousContentChangesNotification。

我的代码（mac app）：

- (void)persistentStoreDidImportUbiquitousContentChangesNotification:(NSNotification *)notif
{
    NSLog(@"%@", notif);
}

- (NSURL *)applicationFilesDirectory
{
    NSString *identifier = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleIdentifier"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSURL *libraryURL = [[[fileManager URLsForDirectory:NSLibraryDirectory inDomains:NSUserDomainMask] lastObject] URLByAppendingPathComponent:identifier];

    if(![fileManager fileExistsAtPath:[libraryURL path]])
    {
        [fileManager createDirectoryAtPath:[libraryURL path] withIntermediateDirectories:YES attributes:nil error:nil];
    }

    return libraryURL;
}

- (NSManagedObjectModel *)managedObjectModel
{
    if (__managedObjectModel)
    {
        return __managedObjectModel;
    }

    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"MyApp" withExtension:@"momd"];
    __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];    
    return __managedObjectModel;
}

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (__persistentStoreCoordinator)
    {
        return __persistentStoreCoordinator;
    }

    NSManagedObjectModel *mom = [self managedObjectModel];
    if (!mom)
    {
        NSLog(@"%@:%@ No model to generate a store from", [self class], NSStringFromSelector(_cmd));
        return nil;
    }

    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSURL *applicationFilesDirectory = [self applicationFilesDirectory];
    NSError *error = nil;

    NSDictionary *properties = [applicationFilesDirectory resourceValuesForKeys:[NSArray arrayWithObject:NSURLIsDirectoryKey] error:&error];

    if (!properties)
    {
        BOOL ok = NO;
        if ([error code] == NSFileReadNoSuchFileError)
        {
            ok = [fileManager createDirectoryAtPath:[applicationFilesDirectory path] withIntermediateDirectories:YES attributes:nil error:&error];
        }
        if (!ok)
        {
            [[NSApplication sharedApplication] presentError:error];
            return nil;
        }
    }
    else
    {
        if ([[properties objectForKey:NSURLIsDirectoryKey] boolValue] != YES)
        {
            NSString *failureDescription = [NSString stringWithFormat:@"Expected a folder to store application data, found a file (%@).", [applicationFilesDirectory path]]; 

            NSMutableDictionary *dict = [NSMutableDictionary dictionary];
            [dict setValue:failureDescription forKey:NSLocalizedDescriptionKey];
            error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:101 userInfo:dict];

            [[NSApplication sharedApplication] presentError:error];
            return nil;
        }
    }

    NSString *appBundleID = [[NSBundle mainBundle] bundleIdentifier];
    NSURL *storeURL = [applicationFilesDirectory URLByAppendingPathComponent:@"MyApp.sqlite"];
    NSURL *cloudURL = [[fileManager URLForUbiquityContainerIdentifier:nil] URLByAppendingPathComponent:@"Database"];

    NSPersistentStoreCoordinator *coordinator = [[[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:mom] autorelease];
    NSDictionary *optionsDict = [NSDictionary dictionaryWithObjectsAndKeys:appBundleID, NSPersistentStoreUbiquitousContentNameKey, cloudURL, NSPersistentStoreUbiquitousContentURLKey, [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,nil];
    if (![coordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:optionsDict error:&error])
    {
        [[NSApplication sharedApplication] presentError:error];
        return nil;
    }
    __persistentStoreCoordinator = [coordinator retain];

    return __persistentStoreCoordinator;
}

- (NSManagedObjectContext *)managedObjectContext
{
    if (__managedObjectContext)
    {
        return __managedObjectContext;
    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (!coordinator)
    {
        NSMutableDictionary *dict = [NSMutableDictionary dictionary];
        [dict setValue:@"Failed to initialize the store" forKey:NSLocalizedDescriptionKey];
        [dict setValue:@"There was an error building up the data file." forKey:NSLocalizedFailureReasonErrorKey];
        NSError *error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
        [[NSApplication sharedApplication] presentError:error];
        return nil;
    }
    __managedObjectContext = [[NSManagedObjectContext alloc] init];
    [__managedObjectContext setPersistentStoreCoordinator:coordinator];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(persistentStoreDidImportUbiquitousContentChangesNotification:) name:NSPersistentStoreDidImportUbiquitousContentChangesNotification object:coordinator];

    return __managedObjectContext;
}

Answer 1

我遇到了与iOS SDK相同的问题。

要获取“NSPersistentStoreDidImportUbiquitousContentChangesNotification”通知，您必须调用“ - （void）addObserver：（id）观察者选择器：（SEL）aSelector名称：（NSString *）aName对象：（id）anObject”来自NSNotification center。

我添加了这一行

[[NSNotificationCenter defaultCenter] addObserver:masterViewController selector:@selector(notifyiCloud:) name:NSPersistentStoreDidImportUbiquitousContentChangesNotification object:[self persistentStoreCoordinator]];

在AppDelegate的“didFinishLaunchingWithOptions”方法中。在我的情况下，（iOS5）它工作得很好，但我不知道它是否也适用于mac os。

Answer 2

我在iOS和MacOS X上运行CoreData堆时遇到同样的问题。在我的iPhone和iPad之间，NSPersistentStoreDidImportUbiquitousContentChangesNotification：s工作正常。

在Mac上我最终定期执行NSFetchRequest（比如说每5秒）并丢弃结果。只有这样才能收到通知。

我没有得到NSPersistentStoreDidImportUbiquitousContentChangesNotification（带代码示例）

2 个答案: