UICollectionView scrollToItemAtIndexPath
Make sure the collection view has laid out its subviews first along with the resizing of the cell before scrolling. I would suggest moving your scrolling to a place where you're sure all layouts have been completed such as:
- (void)viewDidLayoutSubviews{ [super viewDidLayoutSubviews]; NSIndexPath *indexPath = // compute some index path [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];}
Another option is to call layoutIfNeeded on the UICollectionView before you call scrollToItemAtIndexPath. That way you won't perform the scroll operation every time the parent view's subviews are laid out.