UICollectionView's cellForItemAtIndexPath is not being called

Question

Only my second time using UICollectionView\'s and perhaps I have bitten off more than I can chew but nevertheless:

I am implementing a UICollectionView (myCollection

Answer 1

Just resolved this issue, for a somewhat specific situation.

In my case, I was manually initializing the UICollectionViewController in a parent ViewController, and then adding the UICollectionViewController's view as a subview.

I resolved the issue by calling 'setNeedsLayout' and/or 'setNeedsDisplay' on the collectionView in the parent's viewDidAppear:

- (void)viewDidAppear:(BOOL)animated {
   [super viewDidAppear:animated];
   [_collection.view setNeedsLayout];
   [_collection.view setNeedsDisplay];
}

Answer 2

In my case, set collectionView.prefetchingEnabled = NO; solved my problem. Only works on iOS 10.

Answer 3

I forgot to set the autoresizing mask to false on the collection view:

collectionView.translatesAutoresizingMaskIntoConstraints = false

Answer 4

For a more complicated view hierachy please check this blog. It saved my life!

self.automaticallyAdjustsScrollViewInsets = NO;

Answer 5

In Xcode 7.0.1, we got this problem when we copied a storyboard and accompanying code from another project. The collection view had a custom flow layout set in the storyboard. Solution was to:

• Remove the flow layout in IB
• Compile/run the app
• Set the flow layout back

Now it worked :)

Answer 6

For those who stumble here later.... the reason:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

was not being called was because of the itemSize for the collectionViewFlowLayout's height was too big.

[self.myCollectionViewFlowLayout setItemSize:CGSizeMake(320, 548)];

If I change the height to 410, it will execute cellForItemAtIndexPath.