神奇记录：nil不是合法的NSPersistentStoreCoordinator

Question

我正在使用MagicalRecord，

我是如何设置coreData堆栈的

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Magical record

    [MagicalRecord setupCoreDataStackWithStoreNamed:@"HITO.sqlite"];

我是如何使用它的

- (void)getQuizzessWithCompletion:(void(^)(NSArray *quizzess, BOOL succes, NSError *error))completion {
    NSManagedObjectContext *backGroundContext = [NSManagedObjectContext MR_newPrivateQueueContext] ;
    NSArray *quizzess = [Quiz MR_findAllInContext:backGroundContext];
    BlockSafeRun(completion, quizzess, YES, nil);
}

这就是我得到的东西

2015-06-17 19:50:53.358 HITO[6677:611576] Created new private queue context: <NSManagedObjectContext: 0x61f990>
2015-06-17 19:50:57.230 HITO[6677:611576] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+entityForName: nil is not a legal NSPersistentStoreCoordinator for searching for entity name 'Quiz''

核心数据堆栈似乎尚未正确设置。 我尝试过更改设置核心数据堆栈的方法，但尚未取得成功。

Answer 1

您应该创建默认上下文，然后创建新的私有上下文，然后将默认上下文设置为私有上下文的父级

NSManagedObjectContext *mainContext = [NSManagedObjectContext MR_defaultContext];
NSManagedObjectContext *privateQueueContext = [NSManagedObjectContext MR_newPrivateQueueContext];
[privateQueueContext setParentContext:mainContext];

NSArray *quizzess = = [Quiz MR_findAllInContext:privateQueueContext];