我有一个UITable。我能够成功地对表格进行编辑，以便您可以滑动以删除单元格。但是，自从更新我的Xcode后，当我滑动删除时，我的应用程序崩溃了。
Thread 1
2 - [ViewController configureCell:atIndexPath:]
3 - [ViewController controller:didChangeObject:atIndexPathforChangeType:newIndexPath];
16 - [ViewController tableView:commitEditingStyle:forRowAndIndexPath];
查看上面的线程，16在if子句导致断点，在保存核心数据对象的上下文后检查错误。然后第3行显示NSFetchRequestUpdate被触发而不是NSFetchRequestDelete - 所以应用程序尝试配置单元格而不是删除它。 为什么在更新我的xCode后会发生这种情况？此question有类似的问题，但没有经过验证的答案。
这是我删除单元格的代码：
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
/*Only allow deletion for collection table */
if(_segmentedControl.selectedSegmentIndex == 1) {
NSLog(@"delete ca");
if (editingStyle == UITableViewCellEditingStyleDelete)
{
CollectedLeaf* collectedLeaf = [collectionFetchedResultsController objectAtIndexPath:indexPath];
LeafletPhotoUploader * leafletPhotoUploader = [[LeafletPhotoUploader alloc] init];
leafletPhotoUploader.collectedLeaf = collectedLeaf;
if([LeafletUserRegistration isUserRegistered]) {
[leafletPhotoUploader deleteCollectedLeaf:collectedLeaf delegate:self];
}
// Delete the managed object for the given index path
NSManagedObjectContext *context = [collectionFetchedResultsController managedObjectContext];
[context deleteObject:[collectionFetchedResultsController objectAtIndexPath:indexPath]];
// Save the context.
NSError *error;
if (![context save:&error]) //this causes breakpoint
{
NSLog(@"Failed to save to data store: %@", [error localizedDescription]);
NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
if(detailedErrors != nil && [detailedErrors count] > 0)
{
for(NSError* detailedError in detailedErrors)
{
NSLog(@" DetailedError: %@", [detailedError userInfo]);
}
}
else
{
NSLog(@" %@", [error userInfo]);
}
}
}
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
switch(type) {
case NSFetchedResultsChangeInsert:
[_table insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
NSLog(@"delete called");
[_table beginUpdates];
[_table deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
[_table endUpdates];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[_table cellForRowAtIndexPath:indexPath]
atIndexPath:indexPath];
NSLog(@"fetched update");
break;
case NSFetchedResultsChangeMove:
[_table deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
[_table insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
}
}