Reload data not working in HeaderView in Swift

Question

I am not able to update the data of the Header View of a CollectionView. This header view is a subclass of UICollectionReusableView.

I tried to call a method for reloading this data in different places but none of them is triggering the update. To see the updated data I have to close and open the app again.

Collection View:

    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {

        guard kind == UICollectionView.elementKindSectionHeader else {
            fatalError("Unexpected element kind.")
        }

        let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "ProfileHeaderView", for: indexPath) as! ProfileHeaderView

         header?.reloadData()
//        headerView.userNameLabel.text = defaults.string(forKey: "username")

        return headerView
    }

Header View:

class ProfileHeaderView: UICollectionReusableView {

    @IBOutlet weak var userNameLabel: UILabel!

    func reloadData() {

        let defaults = UserDefaults.standard
        usernameTextLabel.text = defaults.string(forKey: "username")

    }

I also tried to call reloadData() on ViewWillAppear and ViewDidAppear

Answer 1

You can try getting the header, for example:

func reloadHeaderData() {
    guard let header = collectionView.supplementaryView(forElementKind: UICollectionView.elementKindSectionHeader, at: YourIndexPath) as? ProfileHeaderView else { return }
    header.reloadData()
}