UICollectionView cell subviews do not resize

Question

In a CollectionView, some cells should have an additional subview or layer. The CollectionView can be told to resize it\'s cells, thus all content

Answer 1

I'm adding subView and constraint programmatically, the following code works for me:

lazy var imageView: UIImageView = { [unowned self] in
    let imageView = UIImageView(frame: self.contentView.frame)
    imageView.contentMode = .scaleAspectFill
    imageView.clipsToBounds = true

    return imageView
}() 

func updateCellWith(image: UIImage) {

    contentView.subviews.forEach { $0.removeFromSuperview() }

    contentView.addSubview(imageView)
    imageView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 0).isActive = true
    imageView.leftAnchor.constraint(equalTo: contentView.leftAnchor, constant: 0).isActive = true
    imageView.rightAnchor.constraint(equalTo: contentView.rightAnchor, constant: 0).isActive = true
    imageView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: 0).isActive = true

    self.imageView.autoresizingMask.insert(.flexibleHeight)
    self.imageView.autoresizingMask.insert(.flexibleWidth)

    imageView.image = image

}