UICollectionReusableView method not being called

Question

I want my sections in the UICollectionView to have a header with an image.

I have followed these steps:

• at the storyboard, assigned a header a

Answer 1

You answered the question, but in words I understand better:

To make the method being called, add these methods:

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
    return CGSizeMake(60.0f, 30.0f);
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section {
    return CGSizeMake(60.0f, 30.0f);
}

...and go from there.

Answer 2

I have the same issue. I have added referenceSizeForFooterInSection but then also viewForSupplementaryElementOfKind not getting called. I have added this code in viewDidLoad() and it worked for me:

if let flowLayout = self.collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
    flowLayout.sectionFootersPinToVisibleBounds = true   
}

Answer 3

Swift 3.0 (xcode 8.2.1)

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
    return CGSize(width:collectionView.frame.size.width, height:30.0)
}

Answer 4

It seems that you have to give your header a non-zero size or collectionView:viewForSupplementaryElementOfKind:atIndexPath isn't called. So either set the headerReferenceSize property of the flow layout like so:

flowLayout.headerReferenceSize = CGSizeMake(self.collectionView.frame.size.width, 100.f);

Swift 5+

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

or, implement collectionView:layout:referenceSizeForHeaderInSection if you want to vary the size by section.

Answer 5

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

The above code worked for me

Answer 6

Swift 4 Xcode 9.1 Beta 2

Add @objc

@objc func collectionView(_ collectionView: UICollectionView, layout  collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize{
    let size = CGSize(width: 400, height: 50)
    return size
}

Credits: https://medium.com/@zonble/your-delegation-methods-might-not-be-called-in-swift-3-c6065ed7b4cd