尝试将新表行插入节时引发异常

我似乎遇到了一个非常奇怪的问题,这个问题只在尝试将新的NSManagedObject插入新的部分时才会出现。基本上,我的部分是天,单个单元格与时间相关。当我将一个对象移动到当前没有与该日期关联的另一个对象(表行)的日期时,该表需要创建一个新的节并移动该行。我得到的不是正确的结果而是:

严重的应用程序错误。在调用-ControllerIDChangeContent:期间,从NSFetchedResultsController的委托捕获到异常。 * -[NSMutableArray removevobjectatindex:]:索引1超出界限[0。。0]用户信息为(空)

为当前没有其他对象的日期插入新对象似乎工作正常。

controller:didChangeSection:... 似乎是先用insert和delete调用然后 controller:didChangeObject:... 使用NSFetchedResultsChangeMove调用。所以顺序是:

NSFetchedResultsChangeInsert(在didChangeSection中) NSFetchedResultsChangeDelete(在didChangeSection中) NSFetchedResultsChangeMove(在didChangeObject中)

/**
 Delegate methods of NSFetchedResultsController to respond to additions, removals and so on.
 */

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
[self.plainTableView beginUpdates];
}

- (void)controller:(NSFetchedResultsController *)controller
   didChangeObject:(id)anObject
   atIndexPath:(NSIndexPath *)indexPath
 forChangeType:(NSFetchedResultsChangeType)type
  newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tv = self.plainTableView;

switch(type) {
    case NSFetchedResultsChangeInsert:
        [tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
        break;

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

    case NSFetchedResultsChangeUpdate:
        [self configureCell:(UITableViewCell *)[tv cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
        break;

    case NSFetchedResultsChangeMove:
        [tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        // Reloading the section inserts a new row and ensures that titles are updated appropriately.
        [tv reloadSections:[NSIndexSet indexSetWithIndex:newIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
        break;
}
}

- (void)controller:(NSFetchedResultsController *)controller
  didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex
     forChangeType:(NSFetchedResultsChangeType)type {
    switch(type) {
    case NSFetchedResultsChangeInsert:
        [self.plainTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
        break;

    case NSFetchedResultsChangeDelete:
        [self.plainTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
        break;
}
}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
[self.plainTableView endUpdates];
}

实际上,当试图将新行插入到已经存在的日中时,也会发生这种情况,但当为不存在的日插入新行/对象时,则不会发生这种情况。