Add a simple UIView as header of UICollectionView

Question

I have a UICollectionView. I would like to add a header. My header would only be a UILabel. I\'ve :

1) selected \"Section Header\" as a Col

Answer 1

If you don't set the header view in storyboard, you will have to register nib.

Example in viewDidLoad:

- (void)viewDidLoad
{
    [self.collectionView registerClass:NSStringFromClass([YourOwnSubClass class]) forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderViewIdentifier"];
}

Anyway, you can also subclass UICollectionReusableView.

@interface YourOwnSubClass : UICollectionReusableView

then call delegate in your class example:

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView
           viewForSupplementaryElementOfKind:(NSString *)kind
                                 atIndexPath:(NSIndexPath *)indexPath
{

    YourOwnSubClass *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:
                                         UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderView" forIndexPath:indexPath];    
    [self updateSectionHeader:headerView forIndexPath:indexPath];

    return headerView;
}

- (void)updateSectionHeader:(UICollectionReusableView *)header forIndexPath:(NSIndexPath *)indexPath
{
    NSString *text = [NSString stringWithFormat:@"header #%i", indexPath.row];
    header.label.text = text;
}

And don't forget to set header size in collection view or in flow layout so header view will be visible.

Answer 2

None of above works if you forgot to enable accessory in your XIB file, don't forget to activate your desired section!

Answer 3

In swift like below

Register Header View

collectionView.register(HeaderView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "headerView")

In UICollectionViewDataSource

func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {

    let headerView = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: "headerView", forIndexPath: indexPath)

    headerView.frame.size.height = 100

    return headerView
}

Important is that you are supply the flow layout with the header size

flowLayout.headerReferenceSize = CGSize(width: self.collectionView.frame.size.width, height: 100)

Otherwise the data source method will not get called