表與NSFetchedResultsController招行與添加部分

Question

我的UITableView與NSFetchedResultsController

NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] 
                  initWithFetchRequest:[self dataFetchRequest] 
                  managedObjectContext:[MLCoreDataService sharedInstance].managedObjectContext 
                  sectionNameKeyPath:@"checked" 
                  cacheName:nil]; 
aFetchedResultsController.delegate = self; 

我實現

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

    switch(type) { 
     case NSFetchedResultsChangeInsert: 
      [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; 
      break; 

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

     case NSFetchedResultsChangeUpdate: 
      [(MLItemTableViewCell*)[tableView cellForRowAtIndexPath:indexPath] setItem:anObject]; 
      break; 

     case NSFetchedResultsChangeMove: 

      [tableView moveRowAtIndexPath:indexPath toIndexPath:newIndexPath]; 
      break; 
    } 

    [self.tableView reloadData]; 
} 

當我改變我行「檢查」實體財產我接到一個電話到

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

帶有NSFetchedResultsChangeMove

當編輯之前和之後有相同的部分數量時，所有的都是正確的。 但是，當我只有一個部分，編輯一行應該去下一節後，我得到了以下錯誤

2014-07-27 17:37:43.384 mlist[34340:60b] CoreData: error: Serious application error. Exception was caught during Core Data change processing. This is usually a bug within an observer of NSManagedObjectContextObjectsDidChangeNotification. Invalid update: invalid number of sections. The number of sections contained in the table view after the update (2) must be equal to the number of sections contained in the table view before the update (1), plus or minus the number of sections inserted or deleted (0 inserted, 0 deleted). with userInfo (null) 
2014-07-27 17:37:43.420 mlist[34340:60b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of sections. The number of sections contained in the table view after the update (2) must be equal to the number of sections contained in the table view before the update (1), plus or minus the number of sections inserted or deleted (0 inserted, 0 deleted).' 

當我嘗試插入刪除didChangeObject ......方法與類型的NSFetchedResultsChangeMove我有同樣的錯誤與部分中的行數。

有沒有常見的解決方法？什麼是正確的做法呢？

Answer 1

問題所作的

[self.tableView beginUpdates]; 
[self.tableView endUpdates]; 

NSFetchedResultsControllerDelegate

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

    switch(type) { 
     case NSFetchedResultsChangeInsert:{ 
      [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; 
     } 
     break; 

     case NSFetchedResultsChangeDelete:{ 
      [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade]; 
     } 
     break; 

     case NSFetchedResultsChangeUpdate:{ 
      [(MLItemTableViewCell*)[tableView cellForRowAtIndexPath:indexPath] setItem:anObject]; 
     } 
     break; 

     case NSFetchedResultsChangeMove:{ 
      if (_sectionsChanged) { 
       [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade]; 
       [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; 

       _sectionsChanged = NO; 
      } else { 
       [tableView moveRowAtIndexPath:indexPath toIndexPath:newIndexPath]; 
      } 
     } 
     break; 
    } 

} 

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type { 

    switch(type) { 
     case NSFetchedResultsChangeInsert: 
      [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] 
          withRowAnimation:UITableViewRowAnimationFade]; 
      break; 

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

    _sectionsChanged = YES; 
} 

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller { 
    [self.tableView beginUpdates]; 
} 

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller { 
    [self.tableView endUpdates];  
}