找不到实体的NSManagedObjectModel

Question

这是viewDidLoad中fetchRequest的代码,代码遵循这里的教程,只是我以编程方式链接导航控制器和tableview,而不是使用界面构建器.实体ProductInfo存在.但是,当我运行程序时,我收到错误:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name 'ProductInfo''

我已经重置模拟器,因为它是一个旧模型,但错误仍然发生.我也切换到使用FetchedResultsController,但问题仍然存在.问题是因为这些fetchedResultsController方法不在appdelegate中？它们目前位于TableViewController中.我怎么解决这个问题？

viewDidLoad方法:

- (void)viewDidLoad{

NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription * entity = [NSEntityDescription entityForName:@"ProductInfo" inManagedObjectContext:context];
[fetchRequest setEntity:entity];
NSError * error;
self.productInfos = [_context executeFetchRequest:fetchRequest error:&error];
[fetchRequest release];
[super viewDidLoad];}

ProductInfo.h:

@class ProductDetails;

@interface ProductInfo : NSManagedObject {
@private
}
@property (nonatomic, retain) NSString * productName;
@property (nonatomic, retain) NSString * productPrice;
@property (nonatomic, retain) ProductDetails * details;

@end

FetchedResultsController

-(NSFetchedResultsController *)fetchedResultsController {
if (_fetchedResultsController != nil) {
    return _fetchedResultsController;
}

NSFetchRequest  * fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription * entity  = [NSEntityDescription entityForName:@"ProductInfo" inManagedObjectContext:_context]; //line that is causing the problem
[fetchRequest setEntity:entity];

NSSortDescriptor * sort = [[NSSortDescriptor alloc] initWithKey:@"productInfos.productName" ascending:YES];
[fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];

[fetchRequest setFetchBatchSize:20];

NSFetchedResultsController * theFetchedResultsController  = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext: _context sectionNameKeyPath:nil cacheName:@"Root"]; 
self.fetchedResultsController = theFetchedResultsController;
_fetchedResultsController.delegate = nil;

[sort release];
[fetchRequest release];
[theFetchedResultsController release];

return _fetchedResultsController;

}

任何帮助非常感谢.谢谢你提前.

如果我粘贴的上述片段没有帮助,我也将整个项目与数据模型结合在一起.

http://www.mediafire.com/?5cns4q0sv9hqn6s

Answer 1

每次交换机开发计算机时都会发生这种情况.我要做的是

1. 从模拟器中卸载应用程序.
2. 重命名存储UIManagedDocument的数据库文件.
3. 执行Build Clean.
4. 构建并运行应用程序.