我正在尝试让我的应用程序与iCloud配合使用,如果用户请求,该应用程序需要将现有的本地存储迁移到普适存储。
在Apple开发者论坛和其他地方调查后,我采取了这种方法,但它并不总是有效。实际上,我曾经看到它起作用过,但是只有在装有iCloud的设备B上出现了数次崩溃之后。
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil)
return persistentStoreCoordinator;
NSURL *legacyStoreUrl = [NSURL fileURLWithPath:[[self applicationDocumentsDirectory] stringByAppendingPathComponent:[self activeStoreFilenameUpgraded:NO]]];
NSURL *upgradedStoreUrl = [NSURL fileURLWithPath:[[self applicationDocumentsDirectory] stringByAppendingPathComponent:[self activeStoreFilenameUpgraded:YES]]];
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if ((IOS_VERSION_GREATER_THAN_OR_EQUAL_TO(@"5.0")) && (self.iCloudEnabled)) {
NSPersistentStoreCoordinator* psc = persistentStoreCoordinator;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSDictionary *cloudOptions = nil;
NSDictionary *localOptions = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,
nil];
NSURL *cloudURL = [fileManager URLForUbiquityContainerIdentifier:@"<CONTAINER ID>"];
NSString *coreDataCloudContent = [[cloudURL path] stringByAppendingPathComponent:[NSString stringWithFormat:@"logs%d",[self activeStoreIndex]]];
if ([coreDataCloudContent length] != 0) {
// iCloud is available
cloudURL = [NSURL fileURLWithPath:coreDataCloudContent];
cloudOptions = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,
@"MyAppStore", NSPersistentStoreUbiquitousContentNameKey,
cloudURL, NSPersistentStoreUbiquitousContentURLKey,
nil];
} else {
// iCloud is not available
}
NSError *error = nil;
[psc lock];
if(migrateStore) {
migrateStore = NO;
NSPersistentStore *srcPS = [psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:legacyStoreUrl
options:localOptions
error:&error];
if (![psc migratePersistentStore:srcPS
toURL:upgradedStoreUrl
options:cloudOptions
withType:NSSQLiteStoreType
error:&error]) {
NSLog(@"Error migrating data: %@, %@ / %@ / %@", error, [error userInfo], legacyStoreUrl, upgradedStoreUrl);
abort();
}
}
else {
if (![psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:upgradedStoreUrl
options:(cloudOptions ? cloudOptions : localOptions)
error:&error]) {
NSLog(@"Unresolved iCloud error %@, %@", error, [error userInfo]);
abort();
}
}
[psc unlock];
[[NSNotificationCenter defaultCenter] postNotificationName:@"RefetchAllDatabaseData" object:self userInfo:nil];
} else {
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,
nil];
NSError *error = nil;
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:legacyStoreUrl options:options error:&error]) {
// error
abort();
}
}
return persistentStoreCoordinator;
}