collectionView hide my custom view in header - ios

Question

I'm trying to add customView into headerView of my collectionView. Here's my code:
I registed the headerView class in viewDidLoad:
collectionView.register(SearchReuseView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "reuseCell")
Then I setup the collectionView:
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
var reuseView: UICollectionReusableView?
if indexPath.section == 0 || banners.count == 0 {
let view = UICollectionReusableView(frame: CGRect.zero)
reuseView = view
} else {
if kind == UICollectionElementKindSectionHeader {
let view = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "reuseCell", for: indexPath) as! SearchReuseView
view.backgroundColor = .black
view.delegate = self
view.frame = CGRect(x: 0, y: 0, width: collectionView.frame.width, height: 100)
view.item = banners[indexPath.section % banners.count]
return view
}
}
return reuseView!
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
if section == 0 {
return CGSize.zero
}
return CGSize(width: collectionView.frame.width, height: 100)
}
But when I run on Simulator, the collectionView shows the header but nothing inside.
Here is code of SearchReuseView :
class SearchReuseView: UICollectionReusableView {
weak var delegate: SearchReuseDelegate?
let adImageView: UIImageView = {
let img = UIImageView()
img.translatesAutoresizingMaskIntoConstraints = false
img.contentMode = .scaleAspectFit
return img
}()
override init(frame: CGRect) {
super.init(frame: frame)
self.setupViews()
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
self.setupViews()
}
func setupViews() {
backgroundColor = .black
adImageView.isUserInteractionEnabled = true
adImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTap)))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .bottom, relatedBy: .equal, toItem: self.adImageView, attribute: .bottom, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .right, relatedBy: .equal, toItem: self.adImageView, attribute: .right, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .top, relatedBy: .equal, toItem: self.adImageView, attribute: .top, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .left, relatedBy: .equal, toItem: self.adImageView, attribute: .left, multiplier: 1, constant: 0))
addSubview(adImageView)
}
var item: Banner! {
didSet {
guard let img = item.img else {return}
let url = URL(string: "\(img)")
self.adImageView.kf.setImage(with: url, placeholder: nil, options: [.transition(ImageTransition.fade(1))], progressBlock: { (receivedSize, totalSize) in
}) { (image, error, cacheType, imageURL) in
if error != nil {}
}
}
}
#objc func handleTap(){
guard let link = item.link else {
return
}
delegate?.didTapAds(link: link)
}
}

Answer 1

I wonder why your app is not crashing you should add subview first then add constraints to it
Replace your code with following code
func setupViews() {
backgroundColor = .black
addSubview(adImageView)
addSubview.translatesAutoresizingMaskIntoConstraints = false
adImageView.isUserInteractionEnabled = true
adImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTap)))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .bottom, relatedBy: .equal, toItem: self.adImageView, attribute: .bottom, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .right, relatedBy: .equal, toItem: self.adImageView, attribute: .right, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .top, relatedBy: .equal, toItem: self.adImageView, attribute: .top, multiplier: 1, constant: 0))
self.addConstraint(NSLayoutConstraint(item: self, attribute: .left, relatedBy: .equal, toItem: self.adImageView, attribute: .left, multiplier: 1, constant: 0))
}
Hope it is helpful

Answer 2

if kind == UICollectionElementKindSectionHeader {
let view = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "reuseCell", for: indexPath) as! SearchReuseView
view.backgroundColor = .black
view.delegate = self
view.frame = CGRect(x: 0, y: 0, width: collectionView.frame.width, height: 100) //delete this line
view.item = banners[indexPath.section % banners.count]
return view
}
I delete the line set frame for header view and it's works