我第一次接触Core Data时,在设备上运行代码时遇到以下错误,但在模拟器上工作正常。



我的一些可能导致此问题的方法:

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

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil)
    {
        __managedObjectContext = [[NSManagedObjectContext alloc] init];
        [__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:@"RugbyOnTv" 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;
    }

    NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"RugbyOnTV.sqlite"];

    NSURL *storeUrl = [NSURL fileURLWithPath:storePath];

    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];

    NSError *error = nil;
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];


    if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {

        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }

    return __persistentStoreCoordinator;
}


    - (NSString *)applicationDocumentsDirectory {

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
        return basePath;
    }

编辑

我从Apple的CoreDataBooks复制并粘贴了ManagedObjectContext方法(如下),现在可以使用了。
- (NSManagedObjectModel *)managedObjectModel {
    if (managedObjectModel != nil) {
        return managedObjectModel;
    }
    managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];
    return managedObjectModel;
}

最佳答案

我有与原始帖子完全相同的错误消息。我为此花了好几个小时。
这是我的AppDelegate.m中的这一行。

NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"[same with name of xcdatamodeld]" withExtension:@"momd"];

对于在那里搜索此错误消息并找到该线程的任何人。

您必须确保它说的是[与xcdatamodeld的名称相同]...。
由于某种原因,我的项目名称在那里,而不是数据模型名称。

更改它,它立即起作用.....

感谢Rock&Muller的贡献....您救了我几天!!

加兹

关于objective-c - 无法使用nil模型创建NSPersistentStoreCoordinator,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/7361187/

10-10 14:22
查看更多