我正在使用iCloud与核心数据同步工作正常。现在我想添加开/关切换（迁移存储）。如果我将商店迁移到iCloud到本地工作正常，但如果迁移回iCloud数据获得重复。即使我试图在迁移之前删除无处不在的容器没有帮助。我无法进行重复数据删除，因为重复数据后没有调用“StoreDidImportUbiquitousContent”方法。
以下代码：
-(NSURL *)storeURL
{
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Expns.sqlite"];
return storeURL;
}
- (void)moveStoreFileToICloud:(NSURL*)fileURL
{
NSPersistentStoreCoordinator * persistentStoreCoordinator = self.persistentStoreCoordinator;
id sourceStore = [[persistentStoreCoordinator persistentStores] firstObject];
if (!sourceStore) {
NSLog(@" failed to add old store");
} else {
NSLog(@" Successfully added store to migrate");
bool moveSuccess = NO;
NSError *error;
NSLog(@" About to migrate the store...");
// Now migrate the store using the iCloud options
id migrationSuccess = [self.persistentStoreCoordinator migratePersistentStore:sourceStore toURL:[self storeURL] options:[self icloudStoreOptions] withType:NSSQLiteStoreType error:&error];
if (migrationSuccess) {
moveSuccess = YES;
NSLog(@"store successfully migrated");
// Now delete the local file
if (shouldDelete) {
NSLog(@" deleting local store");
[self deleteLocalStore];
} else {
NSLog(@" not deleting local store");
}
}
else {
NSLog(@"Failed to migrate store: %@, %@", error, error.userInfo);
}
}
}
以上代码正常工作。
//迁移回iCloud
// fileURL是本地文件网址
#include <fstream>
#include "file_to_string.h"
std::string file_to_(const char* name)
{
std::ifstream in(name);
std::string output((std::istreambuf_iterator<char>(in)), std::istreambuf_iterator<char>());
return output;
}
现在，数据会在迁移之前复制。我试图删除无处不在的容器也没有帮助。