ios - 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 Collection View accessory in the IB.

2) created a Collection Reusable View in the IB, on the side, declared as collectionViewHeader.

3) added those lines :

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

            return collectionViewHeader;
    }
    return nil;
}

But they are never called.

Do I have to create a class just for that label in order to use

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

?

Why isn't it as simple as the UITableView where you just drag and drop whatever header you want ?! Things are so complicated with UICollectionView...

question from:https://stackoverflow.com/questions/21731318/add-a-simple-uiview-as-header-of-uicollectionview

Answer 1

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