NSManagedObjectModel 合并模型FromBundles 错误答案

【问题标题】：NSManagedObjectModel mergedModelFromBundles errorNSManagedObjectModel 合并模型FromBundles 错误
【发布时间】：2012-02-12 06:53:09
【问题描述】：

我正在使用 Core Data，并且在我的应用程序一开始就将数据导入数据库时遇到了很多麻烦。
下面是我从我遵循的教程中获取的一些代码。下面概述了我获得 SIGABRT 的要点。任何建议或帮助表示赞赏谢谢

//THIS FUNCTION IS CALLED AFTER MY APP DID FINISHING LOADING IN THE 
//    IN THE APP DELEGATE
-(void)loadData
{
    NSManagedObjectContext *context = [self managedObjectContext];

    NewModel *newModel = (NewModel *)[NSEntityDescription insertNewObjectForEntityForName:@"NewModel" inManagedObjectContext:context];

    //ADD MORE DATA TO ENTITY
}

/**
 Returns the managed object context for the application.
 If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
 */
- (NSManagedObjectContext *) managedObjectContext {

    if (managedObjectContext != nil) {
        return managedObjectContext;
    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        managedObjectContext = [[NSManagedObjectContext alloc] init];
        [managedObjectContext setPersistentStoreCoordinator: coordinator];
    }
    else
    {
        NSLog(@"Error");
    }        
    return managedObjectContext;
}


/**
 Returns the managed object model for the application.
 If the model doesn't already exist, it is created by merging all of the models found in the application bundle.
 */
- (NSManagedObjectModel *)managedObjectModel {

    if (managedObjectModel != nil) {
        return managedObjectModel;
    }
/**********************************************************/    
    //  SIGABRT HAPPENS IN THE NEXT LINE OF CODE
/**********************************************************/    
    managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];    
    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:@"NewModel.db"];
    NSURL *storeUrl = [NSURL fileURLWithPath:storePath];

    // Put down default db if it doesn't already exist
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if (![fileManager fileExistsAtPath:storePath]) {
        NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"LeagueModel" ofType:@"sqlite"];
        if (defaultStorePath) {
            [fileManager copyItemAtPath:defaultStorePath toPath:storePath error:NULL];
        }
    }

    NSError *error = nil;
    persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }    

    return persistentStoreCoordinator;    
}

/**
 Returns the path to the application's Documents directory.
 */
- (NSString *)applicationDocumentsDirectory {
    return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
}

【问题讨论】：

标签： ios core-data nsmanagedobjectcontext nsentitydescription

【解决方案1】：

如果你查看苹果的文档：

mergedModelFromBundles:

返回通过合并在给定包中找到的所有模型创建的模型。

+ (NSManagedObjectModel *)mergedModelFromBundles:(NSArray *)bundles

参数

***bundles***

要搜索的 NSBundle 实例数组。如果指定 nil，则搜索主包。

***Return Value***

通过合并捆绑包中的所有模型创建的模型。

你在需要传递数组的地方传递 nil，这是崩溃的原因。

【讨论】：

> 如果指定 nil，则搜索主包。