我正在尝试从我的应用中的iCloud
中删除NSPersistentStore
同步功能。迁移不会返回任何错误,但是,迁移后,启用iCloud的持久存储中的数据会消失。
以下是我的相关代码:
-(void)setUpCoreDataStackWithICloud
{
//Set up the model and context.
self.model = [NSManagedObjectModel mergedModelFromBundles:nil];
self.context = [[NSManagedObjectContext alloc]init];
[self.context setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
if ([self isiCloudEnabledOnThisDevice]==YES) {
[self setUpiCloud];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setValue:[NSNumber numberWithBool:YES] forKey:@"lastLaunchOfAppiCloudWasEnabled"];
}else self.psc = [self persistentStoreCoordinatorForUserWithoutiCloudEnabled];
[self.context setPersistentStoreCoordinator:self.psc];
}
-(NSPersistentStoreCoordinator*)persistentStoreCoordinatorForUserThatAlreadyMigratedToiCloud
{
NSLog(@"persistentStoreCoordinatorForUserThatAlreadyMigratedToiCloud called");
NSPersistentStoreCoordinator *psc = [[NSPersistentStoreCoordinator alloc]initWithManagedObjectModel:self.model];
NSError *error = nil;
NSPersistentStore *store = [psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:[self newStoreURL]
options:[self iCloudStoreOptions]
error:&error];
if (!store) {
NSLog(@"failed to add store with error %@", [error localizedDescription]);
}else NSLog(@"successfully added store for user that has already migrated to iCloud");
NSDictionary *migrateOptions = @{ NSPersistentStoreRemoveUbiquitousMetadataOption : @YES,
NSMigratePersistentStoresAutomaticallyOption : @YES,
NSInferMappingModelAutomaticallyOption : @YES};
NSError *migrationError = nil;
NSPersistentStore *migratedStore = [psc migratePersistentStore:store toURL:[self testNewestStoreURL] options:migrateOptions withType:NSSQLiteStoreType error:&migrationError];
if (migrationError) {
NSLog(@"Migration from iCloud enabled persistent store was unsuccessful. %@", migrationError.localizedDescription);
}else NSLog(@"The migration from the iCloud enabled persistent store was successful");
NSLog(@"The migrated store is %@", migratedStore);
return psc;
}
-(NSURL*)testNewestStoreURL{
NSString *path = [self itemArchivePathWithAppendedString:@"test.data"];
NSURL *storeURL = [NSURL fileURLWithPath:path];
return storeURL;
}
-(NSURL*)newStoreURL
{
NSString *path = [self itemArchivePathWithAppendedString:@"cloudstore.data"];
NSURL *storeURL = [NSURL fileURLWithPath:path];
return storeURL;
}
答案 0 :(得分:1)
它失败的原因是因为我也在使用映射模型进行模式迁移。根据文档,iCloud不支持此功能。尽管我试图摆脱iCloud,但在涉及架构迁移时,它不允许访问数据。