Uicollectionview's Cellforitematindexpath Is Not Being Called

UICollectionView's cellForItemAtIndexPath is not being called

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.

cellForItemAtIndexPath not called but numberOfItemsInSection does

Ok I think this could be useful for future problems with this...

It was because of constraints on the StoryBoard. I don't really understand why that happens, because I just had fixed an horizontal space. I removed the horizontal space as constraint for that View and everything works fine.

Well, let's life flow.

CollectionView method cellForItemAt indexPath: not being called (Swift)

Hint: CellforRow at:indexPath method won't be called if the size or position of the collectionView is changed before reload, make sure you're not doing that.

cellForItemAtIndexPath is not called for collectionView

[myCollectionView setContentInset:UIEdgeInsetsMake(100, 0, 0, 0)];

Above line solves my problem.

UICollectionView cellForItemAtIndexPath method is not getting called

In your viewDidLoad method you probably want to add:

self.collectionView.delegate = self;
self.collectionView.dataSource = self;
[self.collectionView reloadData];

easy as that.

When does cellForItemAtIndexPath get called?

or are we not supposed to assume any recurrent functionality

That is correct. I can name some calls you can make that will cause it to be called, but that's not the point. The point is that your job is to be ready to answer this question correctly and quickly at any moment. The runtime calls you as often as it thinks might be necessary in order to display the current set of cells and in order to make future scrolling as smooth as possible. As some poet says: "That's all you know and you need to know."

collectionView cellForItemAtIndexPath called only one time -swift - programmatically

The collectionView(_:cellForItemAt:) is called only as the cells appear or are about to appear. It won't call it for all of the cells, but only the visible ones (or those about to scroll into view). It is called in a just-in-time manner.

You can also turn on prefetching (which only works if you turn off “Estimate Size” in the collection view’s “Size inspector” IB or manually set the flow layout’s estimatedItemSize to .zero), but that only makes it a tiny bit more “eager” in terms of fetching cells (fetching those that are going to scroll into view a bit sooner than it would otherwise). It will not fetch all of the cells, but just those that the OS determines might possibly scroll into view soon.

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