nil 不是用于搜索实体名称“GroupMessageInfo”的合法 NSPersistentStoreCoordinator

错误信息：

persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
persistentStoreCoordinator is nil ??
------------ persistentStoreCoordinator is nil ??

- (void)updateGroupTableStatus:(TmpGroupMessageInfo*)info { 

NSManagedObjectContext *ctx = [self createPrivateObjectContext];

[ctx performBlock:^{
    NSPredicate *cdt = [NSPredicate predicateWithFormat:@"groupId == %@ && tableId == %@", info.groupId, info.tableId];

    NSFetchRequest *fetchRequest = [GroupMessageInfo makeRequest:ctx predicate:cdt orderby:nil offset:0 limit:1];
    NSArray *array = [ctx executeFetchRequest:fetchRequest error:nil];
    if ([array count] > 0) {
        for (GroupMessageInfo *msg in array) {
            msg.lastingTime = [NSNumber numberWithLongLong:0];
        }
        [ctx save:nil];
        [self.managedObjectContext performBlock:^{
            [self.managedObjectContext save:nil];
        }];
    }
}];
}

+ (NSFetchRequest*)makeRequest:(NSManagedObjectContext*)ctx predicate:(NSPredicate*)predicate orderby:(NSArray*)orders offset:(int)offset limit:(int)limit {
NSString *className = [NSString stringWithUTF8String:object_getClassName(self)];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:[NSEntityDescription entityForName:className inManagedObjectContext:ctx]];
if (predicate) {
    [fetchRequest setPredicate:predicate];
}
if (orders!=nil) {
    [fetchRequest setSortDescriptors:orders];
}
if (offset>0) {
    [fetchRequest setFetchOffset:offset];
}
if (limit>0) {
    [fetchRequest setFetchLimit:limit];
}
return fetchRequest;}

- (NSManagedObjectContext*)createPrivateObjectContext {
if (_privateManagedObjectContext == nil) {
    _privateManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    [_privateManagedObjectContext setParentContext:self.managedObjectContext];
}

return _privateManagedObjectContext;
  }

- (NSManagedObjectContext *)managedObjectContext {
    if (_managedObjectContext != nil) {
        return _managedObjectContext;
    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        _managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
        [_managedObjectContext setPersistentStoreCoordinator:coordinator];
    }
    return _managedObjectContext;
}

// Returns the managed object model for the application.
// If the model doesn't already exist, it is created from the application's model.
- (NSManagedObjectModel *)managedObjectModel {
    if (_managedObjectModel != nil) {
        return _managedObjectModel;
    }
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"PokerSkyModel" withExtension:@"momd"];
    _managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    return _managedObjectModel;
}

// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    if (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }

    ......

    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:optionsDictionary error:&error]) {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        [self cleanData];
        abort();
    }
    return _persistentStoreCoordinator;
}

我遇到了与你完全相同的事故。最后我发现初始化persistentStoreCoordinator of NSManagedObjectContext cannot被放置在后台线程!

在你的例子中，你在11号线程做了一些CoreData操作，这显然不是主线程.如果这是您第一次访问您的CoreData，那么persistentStoreCoordinator将在您的 No.11 后台线程中设置，从而导致崩溃。您还可以通过输入这些代码来重现崩溃appDidFinishLaunch at AppDelegate

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  
  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
        // your CoreData operation here
    }
    // ...
}

解决方案很简单，只需确保 CoreData 的初始化（或第一次使用它）应该在主线程.当不是时，使用GCD切换到它

dispatch_async(dispatch_get_main_queue(), 0), ^{ 
    // your CoreData initialize here
}