UICollectionView reloadData not functioning properly in iOS 7

I've been updating my apps to run on iOS 7 which is going smoothly for the most part. I have noticed in more than one app that the reloadData method of a UICollectionViewController isn't acting quite how it used to.

I'll load the UICollectionViewController, populate the UICollectionView with some data as normal. This works great on the first time. However if I request new data (populate the UICollectionViewDataSource), and then call reloadData, it will query the data source for numberOfItemsInSection and numberOfSectionsInCollectionView, but it doesn't seem to call cellForItemAtIndexPath the proper number of times.

If I change the code to only reload one section, then it will function properly. This is no problem for me to change these, but I don't think I should have to. reloadData should reload all visible cells according to the documentation.

Has anyone else seen this?

Solution 1:

Force this on the main thread:

dispatch_async(dispatch_get_main_queue(), ^ {
    [self.collectionView reloadData];
});

Solution 2:

In my case, the number of cells/sections in the datasource never changed and I just wanted to reload the visible content on the screen..

I managed to get around this by calling:

[self.collectionView reloadItemsAtIndexPaths:[self.collectionView indexPathsForVisibleItems]];

then:

[self.collectionView reloadData];

Solution 3:

I had exactly the same issue, however I managed to find what was going on wrong. In my case I was calling reloadData from the collectionView:cellForItemAtIndexPath: which looks not to be correct.

Dispatching call of reloadData to the main queue fixed the problem once and forever.

  dispatch_async(dispatch_get_main_queue(), ^{
    [self.collectionView reloadData];
  });

Solution 4:

Reloading some items didn't work for me. In my case, and only because the collectionView I'm using has just one section, I simply reload that particular section. This time the contents are correctly reloaded. Weird that this is only happening on iOS 7 (7.0.3)

[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];