Can't compliant with CoreData + NSFetchedResultsController?

[seedante]

Hi, luke,
Thanks for your code. I get a problem when use CoreData + NSFetchedResultsController as data source instead of NSArray. I use the code:https://github.com/AshFurrow/UICollectionView-NSFetchedResultsController to make UICollectionView works with NSFetchedResultsController just like UITableView together with NSFetchedResultsController.

in NSFetchedResultsController， I use alphabeticPart and orderPart to sort cell, and use alphabeticPart as sectionNameKeyPath, make all same with before, just I use orderPart to sort cell in the section.

but I drag and drop cell in the same section, i.e move B3 to B2, it likes this. Only after I [self.collection reloadData], it looks right. And I move cell to another section, it crashes. This is maybe layout information error. Now I just want to work out with first problem:after move a cell in the same section, onsreen get the same cell.