iOS 10 bug: UICollectionView received layout attributes for a cell with an index path that does not exist

Question

Running my app in a device with iOS 10 I get this error:

UICollectionView received layout attributes for a cell with an index path that does not exist

In iOS 8 and 9 works fine. I have been researching and I have found that is something related to invalidate the collection view layout. I tried to implement that solution with no success, so I would like to ask for direct help. This is my hierarchy view:

->Table view      ->Each cell of table is a custom collection view [GitHub Repo][1]         ->Each item of collection view has another collection view 

What I have tried is to insert

    [self.collectionView.collectionViewLayout invalidateLayout]; 

In the

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView 

of both collection views.

Also I have tried to invalidate layout before doing a reload data, does not work...

Could anyone give me some directions to take?

Answer 1

This happened to me when number of cells in collectionView changed. Turns out I was missing invalidateLayout after calling reloadData. After adding it, I haven't experienced any more crashes. Apple has made some modifications to collectionViews in iOS10. I guess that's the reason why we are not experiencing same problem on older versions.

Here's my final code:

[self.collectionView reloadData]; [self.collectionView.collectionViewLayout invalidateLayout];  //Swift 4.2 Version collectionView.reloadData() collectionView.collectionViewLayout.invalidateLayout() 

Answer 2

When you have custom layout, remember to clear cache (UICollectionViewLayoutAttributes) while overriding prepare func

    override func prepare() {        super.prepare()        cache.removeAll()     }