无法使用nil模型创建NSPersistentStoreCoordinator [英] Cannot create an NSPersistentStoreCoordinator with a nil model

问题描述

我的第一次破解Core Data，我在我的设备上运行我的代码时收到以下错误，但它在模拟器上正常工作。

* 由于未捕获异常NSInvalidArgumentException而终止应用程序，原因：无法使用nil模型创建NSPersistentStoreCoordinator

我的一些方法可能导致问题：

   - （NSManagedObjectContext * ）managedObjectContext 
 {
 if（__managedObjectContext！= nil）
 {
 return __managedObjectContext; 
} 
 
 NSPersistentStoreCoordinator * coordinator = [self persistentStoreCoordinator]; 
 if（coordinator！= nil）
 {
 __managedObjectContext = [[NSManagedObjectContext alloc] init]; 
 [__managedObjectContext setPersistentStoreCoordinator：coordinator]; 
} 
 return __managedObjectContext; 
} 
 
 / ** 
返回应用程序的托管对象模型。 
如果模型不存在，则从应用程序的模型创建。 
 * / 
  - （NSManagedObjectModel *）managedObjectModel 
 {
 if（__managedObjectModel！= nil）
 {
 return __managedObjectModel; 
} 
 NSURL * modelURL = [[NSBundle mainBundle] URLForResource：@RugbyOnTvwithExtension：@momd]; 
 __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL：modelURL]; 
 return __managedObjectModel; 
} 
 
 / ** 
返回应用程序的持久存储协调器。 
如果协调器不存在，则会创建它并将应用程序的存储添加到其中。 
 * / 
  - （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错误％@，％@，错误，[错误userInfo]）; 
 abort（）; 
} 
 
 return __persistentStoreCoordinator; 
} 
 
 
  - （NSString *）applicationDocumentsDirectory {
 
 NSArray * paths = NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）; 
 NSString * basePath =（[paths count]> 0）？ [paths objectAtIndex：0]：nil; 
 return basePath; 
} 
  

EDIT

我从Apple的CoreDataBooks复制和粘贴了managedObjectContext方法（下面），现在工作。不确定为什么

   - （NSManagedObjectModel *）managedObjectModel {
 if（managedObjectModel！= nil）{
 return managedObjectModel; 
} 
 managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles：nil] retain]; 
 return managedObjectModel; 
} 
  

解决方案

消息作为原始帖子。我摔了几个小时。
这是我的AppDelegate.m中的这一行。

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

对于任何人搜索此错误消息并找到此主题....尝试这个第一。 / p>

你必须确保它在[与xcdatamodeld的名称相同] ....它是！
由于某种原因，我的项目名称存在，而不是数据模型名称。

更改了它， / p>

感谢Rock& Muller贡献.......你救了我几天！

Gaz。

Been having my first crack at Core Data and I'm getting the following error when running my code on my device, but it works fine on the simulator..

* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Cannot create an NSPersistentStoreCoordinator with a nil model'

Some of my methods that might be causing the problem:

    - (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;
    }

EDIT

I copied and pasted the managedObjectContext method (below) from Apple's CoreDataBooks and it now works..Not really sure why though

- (NSManagedObjectModel *)managedObjectModel {
    if (managedObjectModel != nil) {
        return managedObjectModel;
    }
    managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];    
    return managedObjectModel;
}

解决方案

I had exactly the same error message as the original post. I was wrestling with this for hours. It was this line in my AppDelegate.m.

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

For anyone out there searching this error message and finding this thread....try this first.

You must make sure that where it says [same with name of xcdatamodeld]....that it is!!! For some reason, mine had my project name in there and not the data model name.

Changed it and it worked straight away.....

Thanks to Rock & Muller for contributing.......you saved me days!!

Gaz.

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