How to create UICollectionViewCell programmatically

Try to copy and paste this code into your xcode, it should work

////  HomeVIewController.swift//  Photolancer////  Created by Lee SangJoon  on 9/8/16.//  Copyright © 2016 Givnite. All rights reserved.//import UIKitclass HomeViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {    var collectionview: UICollectionView!    var cellId = "Cell"    override func viewDidLoad() {        super.viewDidLoad()        // Create an instance of UICollectionViewFlowLayout since you cant        // Initialize UICollectionView without a layout        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()        layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)        layout.itemSize = CGSize(width: view.frame.width, height: 700)        collectionview = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)        collectionview.dataSource = self        collectionview.delegate = self        collectionview.registerClass(FreelancerCell.self, forCellWithReuseIdentifier: cellId)        collectionview.showsVerticalScrollIndicator = false        collectionview.backgroundColor = UIColor.whiteColor()        self.view.addSubview(collectionview)    }    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {        return 10    }    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {        let cell = collectionview.dequeueReusableCellWithReuseIdentifier(cellId, forIndexPath: indexPath) as! FreelancerCell        return cell    }}class FreelancerCell: UICollectionViewCell {    let profileImageButton: UIButton = {        let button = UIButton()        button.backgroundColor = UIColor.whiteColor()        button.layer.cornerRadius = 18        button.clipsToBounds = true        button.setImage(UIImage(named: "Profile"), forState: .Normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let nameLabel: UILabel = {        let label = UILabel()        label.font = UIFont.systemFontOfSize(14)        label.textColor = UIColor.darkGrayColor()        label.text = "Bob Lee"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let distanceLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGrayColor()        label.font = UIFont.systemFontOfSize(14)        label.text = "30000 miles"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let pricePerHourLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.darkGrayColor()        label.font = UIFont.systemFontOfSize(14)        label.text = "$40/hour"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let ratingLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGrayColor()        label.font = UIFont.systemFontOfSize(14)        label.text = "4.9+"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let showCaseImageView: UIImageView = {        let imageView = UIImageView()        imageView.backgroundColor = UIColor.whiteColor()        imageView.image = UIImage(named: "Profile")        imageView.translatesAutoresizingMaskIntoConstraints = false        return imageView    }()    let likesLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGrayColor()        label.font = UIFont.systemFontOfSize(14)        label.text = "424 likes"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let topSeparatorView: UIView = {        let view = UIView()        view.backgroundColor = UIColor.darkGrayColor()        view.translatesAutoresizingMaskIntoConstraints = false        return view    }()    let bottomSeparatorView: UIView = {        let view = UIView()        view.backgroundColor = UIColor.darkGrayColor()        view.translatesAutoresizingMaskIntoConstraints = false        return view    }()    let likeButton: UIButton = {        let button = UIButton()        button.setTitle("Like", forState: .Normal)        button.titleLabel?.font = UIFont.systemFontOfSize(18)        button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let hireButton: UIButton = {        let button = UIButton()        button.setTitle("Hire", forState: .Normal)        button.titleLabel?.font = UIFont.systemFontOfSize(18)        button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let messageButton: UIButton = {        let button = UIButton()        button.setTitle("Message", forState: .Normal)        button.titleLabel?.font = UIFont.systemFontOfSize(18)        button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let stackView: UIStackView = {        let sv = UIStackView()        sv.axis  = UILayoutConstraintAxis.Horizontal        sv.alignment = UIStackViewAlignment.Center        sv.distribution = UIStackViewDistribution.FillEqually        sv.translatesAutoresizingMaskIntoConstraints = false;        return sv    }()    override init(frame: CGRect) {        super.init(frame: frame)        addViews()    }    func addViews(){        backgroundColor = UIColor.blackColor()        addSubview(profileImageButton)        addSubview(nameLabel)        addSubview(distanceLabel)        addSubview(pricePerHourLabel)        addSubview(ratingLabel)        addSubview(showCaseImageView)        addSubview(likesLabel)        addSubview(topSeparatorView)        addSubview(bottomSeparatorView)        // Stack View        addSubview(likeButton)        addSubview(messageButton)        addSubview(hireButton)        addSubview(stackView)        profileImageButton.leftAnchor.constraintEqualToAnchor(leftAnchor, constant: 5).active = true        profileImageButton.topAnchor.constraintEqualToAnchor(topAnchor, constant: 10).active = true        profileImageButton.heightAnchor.constraintEqualToConstant(36).active = true        profileImageButton.widthAnchor.constraintEqualToConstant(36).active = true        nameLabel.leftAnchor.constraintEqualToAnchor(profileImageButton.rightAnchor, constant: 5).active = true        nameLabel.centerYAnchor.constraintEqualToAnchor(profileImageButton.centerYAnchor, constant: -8).active = true        nameLabel.rightAnchor.constraintEqualToAnchor(pricePerHourLabel.leftAnchor).active = true        distanceLabel.leftAnchor.constraintEqualToAnchor(nameLabel.leftAnchor).active = true        distanceLabel.centerYAnchor.constraintEqualToAnchor(profileImageButton.centerYAnchor, constant: 8).active = true        distanceLabel.widthAnchor.constraintEqualToConstant(300)        pricePerHourLabel.rightAnchor.constraintEqualToAnchor(rightAnchor, constant: -10).active = true        pricePerHourLabel.centerYAnchor.constraintEqualToAnchor(nameLabel.centerYAnchor).active = true        // Distance depeneded on the priceLabel and distance Label        ratingLabel.rightAnchor.constraintEqualToAnchor(pricePerHourLabel.rightAnchor).active = true        ratingLabel.centerYAnchor.constraintEqualToAnchor(distanceLabel.centerYAnchor).active = true        showCaseImageView.topAnchor.constraintEqualToAnchor(profileImageButton.bottomAnchor, constant: 10).active = true        showCaseImageView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true        showCaseImageView.heightAnchor.constraintEqualToConstant(UIScreen.mainScreen().bounds.width - 20).active = true        likesLabel.topAnchor.constraintEqualToAnchor(showCaseImageView.bottomAnchor, constant: 10).active = true        likesLabel.leftAnchor.constraintEqualToAnchor(profileImageButton.leftAnchor).active = true        topSeparatorView.topAnchor.constraintEqualToAnchor(likesLabel.bottomAnchor, constant: 10).active = true        topSeparatorView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true        topSeparatorView.heightAnchor.constraintEqualToConstant(0.5).active = true        stackView.addArrangedSubview(likeButton)        stackView.addArrangedSubview(hireButton)        stackView.addArrangedSubview(messageButton)        stackView.topAnchor.constraintEqualToAnchor(topSeparatorView.bottomAnchor, constant: 4).active = true        stackView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true        stackView.centerXAnchor.constraintEqualToAnchor(centerXAnchor).active = true        bottomSeparatorView.topAnchor.constraintEqualToAnchor(stackView.bottomAnchor, constant: 4).active = true        bottomSeparatorView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true        bottomSeparatorView.heightAnchor.constraintEqualToConstant(0.5).active = true    }    required init?(coder aDecoder: NSCoder) {        fatalError("init(coder:) has not been implemented")    }}

Your problem lies here. In your viewDidLoad(), you're registering your collectionView cell twice. You are registering the collectionview's cell to your custom cell class in the first line and then in the second line you are registering it to the class UICollectionViewCell.

 collectionView.registerClass(MyCollectionViewCell.self, forCellWithReuseIdentifier: cellReuseIdentifier) collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "collectionCell")

Just remove the second line and your code should work.

I changed Bob Lee answer for swift 4

import UIKitclass noNibCollectionViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {    var collectionview: UICollectionView!    var cellId = "Cell"    override func viewDidLoad() {        super.viewDidLoad()        // Create an instance of UICollectionViewFlowLayout since you cant        // Initialize UICollectionView without a layout        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()        layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)        layout.itemSize = CGSize(width: view.frame.width, height: 700)        collectionview = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)        collectionview.dataSource = self        collectionview.delegate = self        collectionview.register(FreelancerCell.self, forCellWithReuseIdentifier: cellId)        collectionview.showsVerticalScrollIndicator = false        collectionview.backgroundColor = UIColor.white        self.view.addSubview(collectionview)    }    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {        return 10    }    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {        let cell = collectionview.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! FreelancerCell        return cell    }}class FreelancerCell: UICollectionViewCell {    let profileImageButton: UIButton = {        let button = UIButton()        button.backgroundColor = UIColor.white        button.layer.cornerRadius = 18        button.clipsToBounds = true        button.setImage(UIImage(named: "Profile"), for: .normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let nameLabel: UILabel = {        let label = UILabel()        label.font = UIFont.systemFont(ofSize: 14)        label.textColor = UIColor.darkGray        label.text = "Bob Lee"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let distanceLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGray        label.font = UIFont.systemFont(ofSize: 14)        label.text = "30000 miles"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let pricePerHourLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.darkGray        label.font = UIFont.systemFont(ofSize: 14)        label.text = "$40/hour"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let ratingLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGray        label.font = UIFont.systemFont(ofSize: 14)        label.text = "4.9+"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let showCaseImageView: UIImageView = {        let imageView = UIImageView()        imageView.backgroundColor = UIColor.white        imageView.image = UIImage(named: "Profile")        imageView.translatesAutoresizingMaskIntoConstraints = false        return imageView    }()    let likesLabel: UILabel = {        let label = UILabel()        label.textColor = UIColor.lightGray        label.font = UIFont.systemFont(ofSize: 14)        label.text = "424 likes"        label.translatesAutoresizingMaskIntoConstraints = false        return label    }()    let topSeparatorView: UIView = {        let view = UIView()        view.backgroundColor = UIColor.darkGray        view.translatesAutoresizingMaskIntoConstraints = false        return view    }()    let bottomSeparatorView: UIView = {        let view = UIView()        view.backgroundColor = UIColor.darkGray        view.translatesAutoresizingMaskIntoConstraints = false        return view    }()    let likeButton: UIButton = {        let button = UIButton()        button.setTitle("Like", for: .normal)        button.titleLabel?.font = UIFont.systemFont(ofSize: 18)        button.setTitleColor(UIColor.darkGray, for: .normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let hireButton: UIButton = {        let button = UIButton()        button.setTitle("Hire", for: .normal)        button.titleLabel?.font = UIFont.systemFont(ofSize: 18)        button.setTitleColor(UIColor.darkGray, for: .normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let messageButton: UIButton = {        let button = UIButton()        button.setTitle("Message", for: .normal)        button.titleLabel?.font = UIFont.systemFont(ofSize: 18)        button.setTitleColor(UIColor.darkGray, for: .normal)        button.translatesAutoresizingMaskIntoConstraints = false        return button    }()    let stackView: UIStackView = {        let sv = UIStackView()        sv.axis  = UILayoutConstraintAxis.horizontal        sv.alignment = UIStackViewAlignment.center        sv.distribution = UIStackViewDistribution.fillEqually        sv.translatesAutoresizingMaskIntoConstraints = false;        return sv    }()    override init(frame: CGRect) {        super.init(frame: frame)        addViews()    }    func addViews(){        backgroundColor = UIColor.black        addSubview(profileImageButton)        addSubview(nameLabel)        addSubview(distanceLabel)        addSubview(pricePerHourLabel)        addSubview(ratingLabel)        addSubview(showCaseImageView)        addSubview(likesLabel)        addSubview(topSeparatorView)        addSubview(bottomSeparatorView)        // Stack View        addSubview(likeButton)        addSubview(messageButton)        addSubview(hireButton)        addSubview(stackView)        profileImageButton.leftAnchor.constraint(equalTo: leftAnchor, constant: 5).isActive = true        profileImageButton.topAnchor.constraint(equalTo: topAnchor, constant: 10).isActive = true        profileImageButton.heightAnchor.constraint(equalToConstant: 36).isActive = true        profileImageButton.widthAnchor.constraint(equalToConstant: 36).isActive = true        nameLabel.leftAnchor.constraint(equalTo: profileImageButton.rightAnchor, constant: 5).isActive = true        nameLabel.centerYAnchor.constraint(equalTo: profileImageButton.centerYAnchor, constant: -8).isActive = true        nameLabel.rightAnchor.constraint(equalTo: pricePerHourLabel.leftAnchor).isActive = true        distanceLabel.leftAnchor.constraint(equalTo: nameLabel.leftAnchor).isActive = true        distanceLabel.centerYAnchor.constraint(equalTo: profileImageButton.centerYAnchor, constant: 8).isActive = true        distanceLabel.widthAnchor.constraint(equalToConstant: 300)        pricePerHourLabel.rightAnchor.constraint(equalTo: rightAnchor, constant: -10).isActive = true        pricePerHourLabel.centerYAnchor.constraint(equalTo: nameLabel.centerYAnchor).isActive = true        // Distance depeneded on the priceLabel and distance Label        ratingLabel.rightAnchor.constraint(equalTo: pricePerHourLabel.rightAnchor).isActive = true        ratingLabel.centerYAnchor.constraint(equalTo: distanceLabel.centerYAnchor).isActive = true        showCaseImageView.topAnchor.constraint(equalTo: profileImageButton.bottomAnchor, constant: 10).isActive = true        showCaseImageView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true        showCaseImageView.heightAnchor.constraint(equalToConstant: UIScreen.main.bounds.width - 20).isActive = true        likesLabel.topAnchor.constraint(equalTo: showCaseImageView.bottomAnchor, constant: 10).isActive = true        likesLabel.leftAnchor.constraint(equalTo: profileImageButton.leftAnchor).isActive = true        topSeparatorView.topAnchor.constraint(equalTo: likesLabel.bottomAnchor, constant: 10).isActive = true        topSeparatorView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true        topSeparatorView.heightAnchor.constraint(equalToConstant: 0.5).isActive = true        stackView.addArrangedSubview(likeButton)        stackView.addArrangedSubview(hireButton)        stackView.addArrangedSubview(messageButton)        stackView.topAnchor.constraint(equalTo: topSeparatorView.bottomAnchor, constant: 4).isActive = true        stackView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true        stackView.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true        bottomSeparatorView.topAnchor.constraint(equalTo: stackView.bottomAnchor, constant: 4).isActive = true        bottomSeparatorView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true        bottomSeparatorView.heightAnchor.constraint(equalToConstant: 0.5).isActive = true    }    required init?(coder aDecoder: NSCoder) {        fatalError("init(coder:) has not been implemented")    }}