在后台线程中保存数据不起作用

Question

我正在尝试在后台线程中将数据保存在CoreData中，但是它崩溃或不起作用，不知道我在哪里做错了吗？

当我尝试使用主线程时，它可以正常工作，我试图在google上找到后台线程中的一些信息，但是找不到关于它的有用文章。

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谢谢

这是目标-c代码，我尝试过

-(void)insertNameAndSurnameInDataBase:(NSString *)name surname:(NSString *)surname numbers:(NSArray *)numbers labels:(NSArray *)labels{




    NSManagedObjectContext *backgroundMOC = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];

    [backgroundMOC performBlock:^{
        NSError *error;
    NameAndSurname *nameAndSurname = [NSEntityDescription insertNewObjectForEntityForName:@"NameAndSurname" inManagedObjectContext:backgroundMOC];
    NSString *nSurname = [NSString stringWithFormat:@"%@ %@",name,surname];
    nameAndSurname.nameSurname = nSurname;


    if ([backgroundMOC save:&error]) {
    }
    else{

    }

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"NameAndSurname"
                                              inManagedObjectContext:backgroundMOC];


    // predicate
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"nameSurname =[c] %@", nSurname];

    [fetchRequest setEntity:entity];
    [fetchRequest setPredicate:predicate];
    [fetchRequest setReturnsObjectsAsFaults:NO];
    NSArray  *fetchedObjects = [backgroundMOC executeFetchRequest:fetchRequest error:&error];
         if([fetchedObjects count] > 0){
             [numbers enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop){
                  id obj2 = [labels objectAtIndex:idx];
                 obj = [obj stringByReplacingOccurrencesOfString:@" " withString:@""];



                 ContactNumber *phoneNumber = [NSEntityDescription insertNewObjectForEntityForName:@"ContactNumber" inManagedObjectContext:backgroundMOC];
                 phoneNumber.number = obj;
                 phoneNumber.label = obj2;
                 phoneNumber.nameAndSurname = fetchedObjects[0];
                 NSError *error;
                 if ([backgroundMOC save:&error]) {
                 }
                 else{

                 }

            }];
             }

    }];
         }