UICollectionView Custom Cell to fill width In Swift

Question

I\'ve been trying to figure-out how can i make the cell fill the width, as you can see in the picture the width between the cells is too big. i am using custom cell with only on

Answer 1

For my case, autolayout was only allowing the cell to grow to its content size even though I overrode the cell size in the storyboard, conformed to UICollectionViewDelegateFlowLayout, and implemented sizeForItemAt. So I made a dummy UIView the width of the cell's bounds.

UICollectionViewController:

extension CollectionViewController: UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = collectionView.bounds.width - 40
        return CGSize(width: width, height: collectionView.bounds.height / 3)
    }
}

Cell (I'm calling this method on dependency injection):

private func updateViews() {
    let padding:CGFloat = 8
    let innerView = UIView()
    innerView.translatesAutoresizingMaskIntoConstraints = false
    innerView.layer.cornerRadius = 8
    innerView.layer.borderColor = UIColor.black.cgColor
    innerView.layer.borderWidth = 1
    contentView.addSubview(innerView)
    NSLayoutConstraint.activate([
        innerView.widthAnchor.constraint(equalToConstant: bounds.width - padding*2),
        innerView.leadingAnchor.constraint(equalTo: safeAreaLayoutGuide.leadingAnchor, constant: padding),
        innerView.trailingAnchor.constraint(equalTo: safeAreaLayoutGuide.trailingAnchor, constant: -padding),
        innerView.topAnchor.constraint(equalTo: safeAreaLayoutGuide.topAnchor, constant: padding),
        innerView.bottomAnchor.constraint(equalTo: safeAreaLayoutGuide.bottomAnchor, constant: -padding)
    ])
}