核心數據在controllerDidChangeContent嚴重的應用程序錯誤

Question

你好，我現在堆疊下面的錯誤。

CoreData: error: Serious application error.
An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:.
Invalid update: invalid number of sections.
The number of sections contained in the table view after the update (7) must be equal to the number of sections contained in the table view before the update (6), plus or minus the number of sections inserted or deleted (0 inserted, 0 deleted). with userInfo (null)

我的應用程序有多個部分tableView。 只有當我嘗試插入新節記錄時纔會出現錯誤。 如果該部分已經存在，則不會發生錯誤。

相關代碼如下。

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

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject 
     atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type 
     newIndexPath:(NSIndexPath *)newIndexPath 
{ 
    UITableView *tableView = self.tableView; 
    DLog(@"newIndexPath %@",newIndexPath); 
    switch(type) { 
     case NSFetchedResultsChangeInsert: 
      [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; 
      break; 

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

     case NSFetchedResultsChangeUpdate: 
      [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath]; 
      break; 

     case NSFetchedResultsChangeMove: 
      [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade]; 
      [tableView insertRowsAtIndexPaths:@[newIndexPath]withRowAnimation:UITableViewRowAnimationFade]; 
      break; 
    } 
} 

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller 
{ 
    /*NSError *error = nil; 
    if (![[self fetchedResultsController] performFetch:&error]) { 
     DLog(@"Unresolved error %@, %@", error, [error userInfo]); 
     abort(); 
    } 
    [self.tableView reloadData];*/ 
    [self.tableView endUpdates]; 
} 

此外，我把sectionNameKeyPath放在fetchResultsController。 年份列在真實核心數據中不存在，它是擴展列。

NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:@"year" cacheName:@"Master"]; 

Answer 1

我可以通過以下更改來解決錯誤。 只適合處於相同情況的人。

我註釋了以下行。

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

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject 
     atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type 
     newIndexPath:(NSIndexPath *)newIndexPath 
{ 
    UITableView *tableView = self.tableView; 
    DLog(@"newIndexPath %@",newIndexPath); 
    switch(type) { 
     case NSFetchedResultsChangeInsert: 
      [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; 
      break; 

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

     case NSFetchedResultsChangeUpdate: 
      [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath]; 
      break; 

     case NSFetchedResultsChangeMove: 
      [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade]; 
      [tableView insertRowsAtIndexPaths:@[newIndexPath]withRowAnimation:UITableViewRowAnimationFade]; 
      break; 
    } 
} 

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

而且我添加了下面一行。

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller 
{ 
// In the simplest, most efficient, case, reload the table view. 
    NSError *error = nil; 
    if (![[self fetchedResultsController] performFetch:&error]) { 
     DLog(@"Unresolved error %@, %@", error, [error userInfo]); 
     abort(); 
    } 
    [self.tableView reloadData]; 
}