Display Section Header UICollectionReusableView - ios

Question

I was working on iOS application and I have several problem about using UICollectionView cell.
This time, I want to ask about how to display the section header of UICollectionView (UICollectionReusableView)
I already implement the function like below :
public func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath as IndexPath)
var labelHeader = headerView.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
return headerView
default:
assert(false, "Unexpected element kind")
}
}
but, it always give a blank result. please look at the screen shot below

Answer 1

You need to return size of header.
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: collectionView.frame.size.width, height: 123) // you can change sizing here
}
Delegate method
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
var reusableview: UICollectionReusableView? = nil
if kind == UICollectionElementKindSectionHeader {
reusableview = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath) // cellHeader is your identifier
var labelHeader = reusableview.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
}
return reusableview!
}

Answer 2

I have created demo for you. Download and re-use into your code. Cheers!
Download Link : https://www.dropbox.com/sh/vzf2tpe0ccf41tv/AABjdPAoaP2sE7YRtUgersq4a?dl=0

Answer 3

You need to add UILabel on headerView
public func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath as IndexPath)
var labelHeader = headerView.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
headerView.addSubview(labelHeader) //Add UILabel on HeaderView
return headerView
default:
assert(false, "Unexpected element kind")
}
}

Answer 4

Here is my solution. It's done similar to dequeueing a cell/row for indexPathAt.
CollectionView
// size of header
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize{
CGSize(width: collectionView.frame.size.width, height: 123)
}
// content of header
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
guard let headerCell = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: CollectionViewHeader.identifier, for: indexPath) as? CollectionViewHeader else {
return UICollectionReusableView()
}
headerCell.titleLabel.text = "Title"
return headerCell
}
UICollectionReusableView subclass
class CollectionViewHeader: UICollectionReusableView {
let identifier = "headerView"
#IBOutlet weak var titleLabel: UILabel!
}