UICollectionView and Supplementary View (header)

Question

Trying to add a a Supplementary view into my UICollectionView as a header. I\'m having issues getting it to work.

I use a custom UICollectionViewFlowL

Answer 1

I cleaned up my code and removed the UICollectionView I had created in IB and created it all in code. I ran the it again and got a different error and realized I didn't set the delegate or dataSource in IB. I did:

self.collectionView.delegate = self;
self.collectionView.datasource = self;

But that must not have been good enough.

So with UICollectionView created in IB and not setting the delgate/datasource in IB, but rather in the code:

[self.view bringSubviewToFront:self.collectionView];
self.collectionView.collectionViewLayout = collectionViewFlowLayout;
self.collectionView.backgroundColor = [UIColor orangeColor];
self.collectionView.delegate = self;
self.collectionView.dataSource = self;

[self.collectionView registerClass:[DatasetCell class] forCellWithReuseIdentifier:@"cvCell"];

[self.collectionView registerClass:[CollectionHeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"CollectionHeaderView"];

was an issue. I redid it to create the UICollectionView all in code:

UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:collectionViewFlowLayout];
collectionView.translatesAutoresizingMaskIntoConstraints = FALSE;
collectionView.backgroundColor = [UIColor yellowColor];
collectionView.delegate = self;
collectionView.dataSource = self;

[collectionView registerClass:[DatasetCell class] forCellWithReuseIdentifier:@"cvCell"];

[collectionView registerClass:[CollectionHeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"CollectionHeaderView"];

[self.view addSubview:collectionView];

self.collectionView = collectionView;

and i get a different error:

*** Assertion failure in -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:], /SourceCache/UIKit_Sim/UIKit-2380.17/UICollectionView.m:2249
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'could not dequeue a view of kind: UICollectionElementKindSectionHeader with identifier CollectionHeaderView - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'

which I'll try to figure out.

EDIT:

figured it out, I was registering the header incorrectly:

[collectionView registerClass:[CollectionHeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"CollectionHeaderView"];

switched to:

UINib *headerNib = [UINib nibWithNibName:@"CollectionHeaderView" bundle:nil];

[collectionView registerNib:headerNib forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"CollectionHeaderView"];

and everything works. Not entirely sure how the registerClass: wasn't working though.