UICollectionView using different type of cell for each cell

Question

My goal is to create a collection view with 3 different types of collection view cells on each of it cell.

But I get this error from Xcode:

'could not dequeue a view of kind: UICollectionElementKindCell with identifier commands - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'

I have changed the identifier on register to match the identifier on cell, but I still get an error. What is wrong with my code and how do I fix this?

class mainCollectionView: UIView,UICollectionViewDelegateFlowLayout,UICollectionViewDataSource{
    var indexNumber:Int = 0
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 3
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        if indexPath.row == 0 {
            indexNumber = indexPath.row
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "one", for: indexPath) as! oneCollectionViewCell
            cell.backgroundColor = .blue
            return cell
        }else if indexPath.row == 1{
            indexNumber = indexPath.row
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "commands", for: indexPath) as! commandsCollectionViewCell
            cell.backgroundColor = .red
            return cell
        }else{
            indexNumber = indexPath.row
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "threes", for: indexPath) as! threesCollectionViewCell
            cell.backgroundColor = .green
            return cell
        }
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: self.frame.width, height: self.frame.height)
    }

    lazy var collectionViews: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal
        let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
        cv.backgroundColor = UIColor.clear
        cv.dataSource = self
        cv.delegate = self
        return cv
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupViews()
    }

    func setupViews(){
        if indexNumber == 0 {
            collectionViews.register(oneCollectionViewCell.self, forCellWithReuseIdentifier: "one")
        }else if indexNumber == 1 {
            collectionViews.register(commandsCollectionViewCell.self, forCellWithReuseIdentifier: "commmands")
        }else {
            collectionViews.register(threesCollectionViewCell.self, forCellWithReuseIdentifier: "threes")
        }
        collectionViews.translatesAutoresizingMaskIntoConstraints = false
        backgroundColor = UIColor.clear
        addSubview(collectionViews)
        collectionViews.topAnchor.constraint(equalTo: topAnchor, constant: 0).isActive = true
        collectionViews.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 0).isActive = true
        collectionViews.centerYAnchor.constraint(equalTo: centerYAnchor, constant: 0).isActive = true
        collectionViews.centerXAnchor.constraint(equalTo: centerXAnchor, constant: 0).isActive = true
        collectionViews.widthAnchor.constraint(equalTo: widthAnchor, constant: 0).isActive = true
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Answer 1

No if here you must register all in setupViews

 collectionViews.register(oneCollectionViewCell.self, forCellWithReuseIdentifier: "one")

 collectionViews.register(commandsCollectionViewCell.self, forCellWithReuseIdentifier: "commmands")

 collectionViews.register(threesCollectionViewCell.self, forCellWithReuseIdentifier: "threes")

//

This

collectionViews.register(commandsCollectionViewCell.self, forCellWithReuseIdentifier: "commmands")

should bt

collectionViews.register(commandsCollectionViewCell.self, forCellWithReuseIdentifier: "commands")