cellForItemAtIndexPath not called but numberOfItem

Question

This could be a duplicate post but I haven't found the solution in any of this:

I'm setting my UICollectionView as:

UINib *nib = [UINib nibWithNibName:@"CollectionViewCell"
                           bundle:[NSBundle mainBundle]];
[_collectionView registerNib: nib forCellWithReuseIdentifier:@"bCell"];

(I've tried to set delegate, without delegate, etcetera).

But then, only the

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section gets called while

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath doesn't.

I've checked the numberOfItemsInSection I return, and it's always > 0 (it's exactly 17).

I've checked to call [_collectionView reloadData]; and nothing happens either.

I've tried different things but I can't make it work.

Furthermore, my UICollectionView should be here but it's not:

Does anyone have a clue? Thank you.

Answer 1

For me the issue was that I was creating my Collection View programmatically but I had given it CGRectZero as its frame. I was laying it out using Auto Layout after viewDidLoad. If I lay out the collection view while the view controller is loading, it ends up calling cellForItemAtIndexPath: correctly.

Answer 2

Add this to viewDidLoad:

self.automaticallyAdjustsScrollViewInsets = NO;

Answer 3

What helped me was to set the correct itemSize. My cellForItemAtIndexPath was not being called because of the wrong height.

So I set the size at:

[self.myCollectionViewFlowLayout setItemSize:CGSizeMake(170, 300)];

Answer 4

I also face same issue and finally got to know that i have passed wrong class object for collectionViewLayout , i change to UICollectionViewFlowLayout instead of UICollectionViewLayout while creating object for UICollectionView like below its stared calling all delegate method.

 collectionView = UICollectionView(frame: CGRectMake(5, 0, 400, 40) , collectionViewLayout: UICollectionViewFlowLayout())

Answer 5

I meet this problem too. I checked all the possible issues, everything looks ok. Then I tried to changed the reload methods.

[self.colView reloadData] -> [self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:x]];

Then all things worked. However I still don't understand how.

Answer 6

I had faced a similar problem. The issue was with the numberOfItems in section. Your cellForRowAtIndexPath might not be called if either your number of sections or number of rows in section is below zero.