Question

我有UICollectionViewController <NSFetchedResultsControllerDelegate>和CoreData单身经理。因此，当我尝试更新我的对象的一些标题时，我看到错误。

CollectionViewController.m

@interface CollectionViewController ()<NSFetchedResultsControllerDelegate>

@property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
@property (strong, nonatomic) NSManagedObjectContext* managedObjectContext;

@implementation CollectionViewController

- (NSManagedObjectContext*) managedObjectContext {
    if (!_managedObjectContext) {
        _managedObjectContext = [[CoreDataManager sharedManager] managedObjectContext];
    }
    return _managedObjectContext;
}

-(void)pushTheButton: (UIButton*) sender{
    NSIndexPath *indexPath = [self.collectionView indexPathForCell:(PKMapObjectCVCell *)sender.superview.superview];
    SomeObjectClass* object = [self.fetchedResultsController objectAtIndexPath:indexPath];
    [[CoreDataManager sharedManager] changeValueForObject: object.objectID];
}

CoreDataManager.m

@implementation CoreDataManager

@synthesize mainPrivateManagedObjectContext = _mainPrivateManagedObjectContext;
@synthesize managedObjectContext = _managedObjectContext;
@synthesize managedObjectModel = _managedObjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;

+(CoreDataManager*) sharedManager{
    static CoreDataManager* manager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        manager = [[CoreDataManager alloc] init];
    });
    return manager;
}

- (void) changeValueForObject:(NSManagedObjectID*) myobjectID{
    NSManagedObjectContext * bgcontext = [self getContextForBGTask];
    SomeObjectClass * editableObject = [bgcontext objectWithID:myObjectID];
    editableObject.title = @"New Title";

//    [bgcontext updatedObjects];
    [self saveContextForBGTask:bgcontext];

}

- (void)saveContextForBGTask:(NSManagedObjectContext *)bgTaskContext {
    if (bgTaskContext.hasChanges) {
         [bgTaskContext performBlockAndWait:^{ //error on this line:

[错误]错误：严重的应用程序错误。在此期间发生了异常核心数据变更处理。这通常是观察者中的错误 NSManagedObjectContextObjectsDidChangeNotification。左手 ALL或ANY运算符的一侧必须是NSArray或NSSet。 with userInfo（null）CoreData：error：严重的应用程序错误。在Core Data更改处理期间捕获到异常。这是通常是观察者中的一个错误 NSManagedObjectContextObjectsDidChangeNotification。左手 ALL或ANY运算符的一侧必须是NSArray或NSSet。 with userInfo（null）2018-03-21 17：07：42.644646 + 0400 AppName [17860：3506816] ***由于未被捕获而终止应用程序例外＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39;左侧对于ALL或ANY运算符，必须是NSArray或NSSet。

            NSError *error = nil;
            [bgTaskContext save:&error];
        }];
        [self saveDefaultContext:YES]; // Save default context
    }
}
- (NSManagedObjectContext *)managedObjectContext {
    if (_managedObjectContext != nil) {
        return _managedObjectContext;
    }
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];

    _mainPrivateManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    [_mainPrivateManagedObjectContext setPersistentStoreCoordinator:coordinator];

    _managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
    [_managedObjectContext setParentContext:_mainPrivateManagedObjectContext];
    return _managedObjectContext;
}

- (NSManagedObjectContext *)getContextForBGTask {
    NSManagedObjectContext *context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    [context setParentContext:_managedObjectContext];
    return context;
}

那么，我做错了什么？

代码删除对象，工作正常：

 - (void) switchObjectLike:(NSManagedObjectID*) mapObjectID{
    NSManagedObjectContext * bgcontext = [self getContextForBGTask];
    PKMapObj * mapObject = [bgcontext objectWithID:mapObjectID];
    [bgcontext deleteObject:mapObject];
    [self saveContextForBGTask:bgcontext];
}

Answer 1

因此，问题在于NSFetchedResultsController中的谓词。更新某些内容后，NSFetchedResultsController准备重新加载集合视图，并在调用此方法之前：

-(void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
      atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
     newIndexPath:(NSIndexPath *)newIndexPath

它崩溃了，但从未显示出错误。谢谢大家！

Coredata获取结果控制器保存与子NSPrivateQueueConcurrencyType上下文

1 个答案: