UICollectionView

import UIKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {



    override func viewDidLoad() {
        super.viewDidLoad()

        let screenRect = UIScreen.main.bounds
        let rect = CGRect(x: 0, y: 20, width: screenRect.size.width, height: screenRect.size.height / 3)

        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal
        layout.itemSize = CGSize(width: 200, height: 200)
        layout.minimumLineSpacing = 30
        layout.minimumInteritemSpacing = 10
        let collectionView = UICollectionView(frame: rect, collectionViewLayout: layout)
        collectionView.backgroundColor = UIColor.white
        collectionView.register(NSClassFromString("UICollectionViewCell"), forCellWithReuseIdentifier: "reusedCell")
        collectionView.delegate = self
        collectionView.dataSource = self
        self.view.addSubview(collectionView)
    }

    func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell{
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "reusedCell", for: indexPath)
        cell.backgroundColor = UIColor.blue
        return cell
    }

}