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我正在尝试使用 NSFetchedResultController 从 TableView 中删除行，我已经阅读了许多有关如何执行此操作的示例，但我无法弄清楚我做错了什么。我需要这方面的帮助。

这是我得到的错误：

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'no object at index 1 in section at index 0'

这是我的删除代码：

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

    NSLog(@"Deleting object at row %d", indexPath.row);

    // DeleteObject
    NSManagedObject *objToDelete = (NSManagedObject*)[self.fetchedResultsController objectAtIndexPath:indexPath];

    // Delete
    [self.fetchedResultsController.managedObjectContext deleteObject:objToDelete];

    NSError *error = nil;
    [self.fetchedResultsController.managedObjectContext save:&error];
    if(error)
    {
        NSLog(@"DeleteRow caused : %@", error);
    }
}

这是我的 fetchController

- (NSFetchedResultsController *)fetchedResultsController {


    AppDelegate *appdelegate = [[UIApplication sharedApplication]delegate];
    context = [appdelegate managedObjectContext];

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription
                                   entityForName:@"Dagbok" inManagedObjectContext:context];
    [fetchRequest setEntity:entity];


    NSSortDescriptor *sort = [[NSSortDescriptor alloc]
                              initWithKey:@"header" ascending:YES];
    [fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];
    [fetchRequest setFetchBatchSize:40];
    [fetchRequest setRelationshipKeyPathsForPrefetching:[NSArray arrayWithObjects:@"relationship", nil]];

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

    NSArray *matchingdata = [context executeFetchRequest:fetchRequest error:nil];


    return _fetchedResultsController;

}

这是我的 ObjectChanged

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {


    UITableView *tableView = _tabell;

    switch(type) {

        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeUpdate:
            [self configureCell:(VallaDagbokCell*)[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;

        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray
                                               arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:[NSArray
                                               arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}
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1 回答 1

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看来您已经消除了 fetched results 控制器的延迟加载。因此，不清楚 FRC getter 中的获取请求何时被执行。看起来这发生在委托方法删除行之前。

尝试通过重新插入原始延迟加载代码片段来修复您的 FRC getter：

if (_fetchedResultsController != nil) {
    return _fetchedResultsController;
}
于 2013-11-04T10:55:59.117 回答