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

In storyboard/xib UICollectionView property cellSize MUST not be {0, 0}

Answer 2

I was having a similar problem. But instead cellForItemAtIndexPath was called when the number of items was > 1, but not when there was only a single item. I tried many of the proposed solutions here and similar to many I found that it had to do with item sizing. For me the solution was to change the estimate size of the UICollectionView from Automatic to Custom.

Answer 3

Make sure numberOfSectionsInCollectionView returns a positive integer as well.

There has to be at least one section in the collection.

Answer 4

In my case I had the collectionView in a UIStackView with alignment = .center. So the collectionView did not have a width. When setting the stackView.alignment to .fill everything was fine.

Answer 5

Maybe I'm just overlooking it, but it appears your missing your delegate and data source. In your header file, make sure you have added these:

<UICollectionViewDelegate, UICollectionViewDataSource>

and in your viewDidLoad method add this:

self.myCollectionView.delegate = self;
self.myCollectionView.dataSource = self;

Also, if you are loading it via an .xib, make sure you are have connected the IBOutlet to the UICollectionView.

Answer 6

In my case I had to adjust the estimated Content size. content size did not do it.

  let layout = collectionVC.collectionView.collectionViewLayout as! UICollectionViewFlowLayout
    layout.itemSize = CGSize(width: 100, height: 100)
    layout.estimatedItemSize = CGSize(width: 100, height: 100)