Issues with casting celltypes to dequeue

Question

Hi i'm having issues in my cellForItemAt its saying the error below. I don't see why i'm unable to cast the cells. It occurs at the first line of the else statement.

The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in may also be helpful.

Could not cast value of type 'Spoexs.MenuCell2' (0x10d059660) to 'Spoexs.MenuCell1' (0x10d0595c0).

import UIKit
import MIBadgeButton_Swift
class SecondMenuBar: UIView, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
 lazy var collectionView: UICollectionView = {
 let layout = UICollectionViewFlowLayout()
 let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
 cv.backgroundColor = UIColor.rgb(r:240, g:240, b:240)
 cv.dataSource = self
 cv.delegate = self
 return cv
 }()
 let cellId = "cellId"
 let cellId2 = "cellId2"
 let menuItems = ["inventory", "checkout", "scanner"]
 var inventoryController: InventoryTabController?
 override init(frame: CGRect){ //on run
 super.init(frame: frame)
 collectionView.register(MenuCell1.self,
 forCellWithReuseIdentifier: cellId) //registering superclass
 collectionView.register(MenuCell2.self,
 forCellWithReuseIdentifier: cellId) //registering superclass
 addSubview(collectionView)
 addConstraintsWithFormat("H:|[v0]|", views: collectionView)
 addConstraintsWithFormat("V:|[v0]|", views: collectionView)
 let selectedIndexPath = NSIndexPath(item:0, section:0)
 collectionView.selectItem(at: selectedIndexPath as IndexPath, animated: false, scrollPosition: []) //home button glows on run
 //setup horizontal bar
 slider()
 NotificationCenter.default.addObserver(forName: .arrayValueChanged, object: nil, queue: OperationQueue.main) { [weak self] (notif) in
 badge = "\(checkout.count)"
 self?.collectionView.reloadData()
 }
 }
 deinit {
 NotificationCenter.default.removeObserver(self)
 }
 var horizontalBarLeftAnchorConstraint: NSLayoutConstraint?
 func slider() {
 let horizontalBarView = UIView()
 if #available(iOS 10.0, *) {
 horizontalBarView.backgroundColor = UIColor(displayP3Red:0.29, green:0.78, blue:0.47, alpha:0.2)
 } else {
 horizontalBarView.backgroundColor = UIColor.rgb(r:190, g:190, b:190)
 }
 horizontalBarView.translatesAutoresizingMaskIntoConstraints = false
 addSubview(horizontalBarView) //add to hierarchy
 // need x,y coordinate
 horizontalBarLeftAnchorConstraint = horizontalBarView.leftAnchor.constraint(equalTo: self.leftAnchor)
 horizontalBarLeftAnchorConstraint?.isActive = true
 horizontalBarView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
 horizontalBarView.widthAnchor.constraint(equalTo: self.widthAnchor, multiplier: 1/3).isActive = true
 horizontalBarView.heightAnchor.constraint(equalToConstant: 3).isActive = true
 }
 func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
 inventoryController?.scrollToMenuIndex(menuIndex: indexPath.item)
 print("Right here \(indexPath.section)")
 print("Right here \(indexPath.item)")
 }
 func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
 return CGSize(width: frame.width/3, height: frame.height)
 }
 func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
 return 0
 }
 func collectionView(_ collectionView: UICollectionView,
 numberOfItemsInSection section: Int) -> Int {
 return 3
 }
 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
 if indexPath.section == 1{
 let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId2, for: indexPath) as! MenuCell2
 cell.imageView2.setImage(UIImage(named:menuItems[indexPath.section])?.withRenderingMode(.alwaysTemplate), for: .normal)
 cell.imageView2.badgeString = badge
 cell.tintColor = UIColor.rgb(r:255, g:0, b:255) //set tint color
 return cell
 } else{
 let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell1
 cell.imageView1.image = UIImage(named: menuItems[indexPath.section])?.withRenderingMode(.alwaysTemplate)
 cell.tintColor = UIColor.rgb(r:255, g:0, b:255) //set tint color
 return cell
 }
 }
 required init?(coder aDecoder: NSCoder) {
 fatalError("init(coder:) has not been implemented")
 }
}
class MenuCell1: UICollectionViewCell {
 override init(frame: CGRect){
 super.init(frame: frame)
 setupViews()
 }
 required init?(coder aDecoder: NSCoder) {
 fatalError("init(coder:) has not been implemented")
 }
 let imageView1: UIImageView = {
 let iv = UIImageView()
 iv.image = UIImage(named: "")?.withRenderingMode(.alwaysTemplate)
 iv.tintColor = UIColor.rgb(r:144, g:157, b:255)//set tint color of each menu image bg
 return iv
 }()
 override var isSelected: Bool {
 didSet {
 imageView1.tintColor = isSelected ? UIColor.rgb(r:76, g:200, b:120) : UIColor.rgb(r:190, g:190, b:190) //green when selected otherwise grey
 }
 }
 func setupViews() {
 addSubview(imageView1)
 addConstraintsWithFormat("H:[v0(28)]", views: imageView1)
 addConstraintsWithFormat("V:[v0(28)]", views: imageView1)
 addConstraint(NSLayoutConstraint(item: imageView1, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier:1, constant: 0)) //center menu icons
 addConstraint(NSLayoutConstraint(item: imageView1, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier:1, constant: 0))
 }
}
class MenuCell2: UICollectionViewCell {
 override init(frame: CGRect){
 super.init(frame: frame)
 setupViews()
 }
 required init?(coder aDecoder: NSCoder) {
 fatalError("init(coder:) has not been implemented")
 }
 let imageView2: MIBadgeButton = {
 let button = MIBadgeButton()
 var image = UIImage(named: "home")?.withRenderingMode(.alwaysTemplate)
 button.setImage(image, for: .normal)
 button.badgeString = badge
 button.isUserInteractionEnabled = false
 button.tintColor = UIColor.rgb(r:190, g:190, b:190) //intital button tint grey
 return button
 }()
 override var isSelected: Bool {
 didSet {
 imageView2.tintColor = isSelected ? UIColor.rgb(r:76, g:200, b:120) : UIColor.rgb(r:190, g:190, b:190) //green when selected otherwise grey
 }
 }
 func setupViews() {
 addSubview(imageView2)
 addConstraintsWithFormat("H:[v0(28)]", views: imageView2)
 addConstraintsWithFormat("V:[v0(28)]", views: imageView2)
 addConstraint(NSLayoutConstraint(item: imageView2, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier:1, constant: 0)) //center menu icons
 addConstraint(NSLayoutConstraint(item: imageView2, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier:1, constant: 0))
 }
}

Answer 1

Your code for registering the cell classes is wrong:

collectionView.register(MenuCell1.self, forCellWithReuseIdentifier: cellId)
collectionView.register(MenuCell2.self, forCellWithReuseIdentifier: cellId) // <-- probably not intended

You are registering both classes for the same cellId, one should be cellId2:

collectionView.register(MenuCell1.self, forCellWithReuseIdentifier: cellId)
collectionView.register(MenuCell2.self, forCellWithReuseIdentifier: cellId2)

• Umair Afzal: @ValerioZhang Accept the answer if it solved your problem.

Answer 2

The problem is this line:

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell1

The cell you have registered for this reuse identifier is MenuCell2, so that is what you get. You cannot then magically turn it into a MenuCell1!