Getting section index from UICollectionView (or the other direction)

Question

Given a section index, how can I get the UICollectionReusableView for the section header?

Or how can I get the section index from the UICollectionReusableView object.

I read this: How to get the index path of a UICollectionView header?, and similar posts but it doesn't work for me.

My sections are dynamic controlled by a NSFetchedResultsController and there are multiple inserts, deletion and re-inserts. I suspect that the indices I store in collectionView:viewForSupplementaryElementOfKind:atIndexPath and collectionView:didEndDisplayingSupplementaryView:forElementOfKind:atIndexPath: are invalidated at some point.

Answer 1

Eventually I found a solution. Ugly but it seems to work:

- (SUGalleryHeaderView *)headerForSection:(NSInteger)section
{
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:section];
    NSString *kind = UICollectionElementKindSectionHeader;
    UICollectionViewLayoutAttributes *attr = 
        [self.collectionViewLayout layoutAttributesForSupplementaryViewOfKind:kind atIndexPath:indexPath];

    for (SUGalleryHeaderView *header in headersActive) {
        if (CGRectEqualToRect(header.frame, attr.frame)) {
            return header;
        }
    }
    return nil;
}

Originally posted here: Getting supplementary view at specified index in UICollectionView