Question

我已经使用NSFetchedResultController将数据加载到UITableView中。使用MagicalRecord进行coredata操作。

我在默认上下文中创建了 NSFetchedResultsController ，在 didSelectRowAtIndexPath 上我已经使用了它，如下所示

-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
UserEntity * user = [userFetchedResultsController objectAtIndexPath:indexPath];

// do some changes to user Object 
}

稍后在保存按钮点击操作后，我试图保存如下

[[NSManagedObjectContext defaultContext] saveToPersistentStoreWithCompletion:^(BOOL success, NSError *error) {
    DLog(@" isSaved : %d ",success);
}];

但未保存更改，

2014-09-22 17:12:50.752 _block_invoke [Line 210] has Changed 1
2014-09-22 17:12:50.752 MR_saveWithOptions:completion:](0x7fca7214e7d0) → Saving <NSManagedObjectContext (0x7fca7214e7d0): *** DEFAULT ***> on *** MAIN THREAD ***

2014-09-22 17:12:50.753 MR_saveWithOptions:completion:](0x7fca7214e7d0) → Save Parents? 1

2014-09-22 17:12:50.753 MR_saveWithOptions:completion:](0x7fca7214e7d0) → Save Synchronously? 0

2014-09-22 17:12:50.759 MR_saveWithOptions:completion:](0x7fca7214c430) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING

2014-09-22 17:12:50.759 _block_invoke_2 [Line 213]  isSaved : 0

显然，NSManagedObject有更改，但是日志显示没有更改，任何人都可以解释这个吗？

更新

我可以在defaultContext的UpdatedObjects列表中看到更改的对象，但仍然没有保存不工作

DLog(@" updated Objects %@ ",  [[NSManagedObjectContext defaultContext] updatedObjects]);

 updated Objects {(
<UserEntity: 0x1780cd4a0> (entity: UserEntity; id: 0xd000000000040000 <x-coredata://1E0810DA-1A23-4337-B279-3957BE4D207F/UserEntity/p1> ; data: {
   // entity data removed 
})
)} 

NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING

任何建议都会非常有用

更新2：

下面是我如何创建NSFetchedResultsController

-(NSFetchedResultsController*) userFetchedResultsController {
@autoreleasepool {
    if(userFetchedResultsController == nil){

        NSFetchRequest *fetchRequest = [UserEntity requestAllSortedBy:@"userName" ascending:YES];
        [fetchRequest setFetchBatchSize:10];

        NSFetchedResultsController *theFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[NSManagedObjectContext defaultContext] sectionNameKeyPath:nil cacheName:nil];

        userFetchedResultsController = theFetchedResultsController;
        userFetchedResultsController.delegate = self;
    }
    return userFetchedResultsController;
}
}

Answer 1

这实际上是我身边的一个逻辑错误，它重置了NSManagedObject值，导致上下文没有变化。

立即更新工作正常。

魔法记录NSFetchedResultsController NSManagedObject更改保存不起作用

1 个答案: