didDeselectItemAt not working after scrolling swift - swift

Question

I am designing a menu tab bar with collectionview, and I want to change the color of the label when it is selcted.
Everything works fine but when the selected item is not in the screen anymore(due to scroll out of the screen), then the func inside didDeselectItemAt is not working anymore.
Is there anyway to solve this problem? Below is the code:
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
if collectionView == self.productMenuCollectionView {
guard let cell = self.productMenuCollectionView.cellForItem(at: indexPath) as? ProductMenuCollectionViewCell else {
return
}
cell.label.textColor = UIColor.black
} else {
}
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if collectionView == self.productMenuCollectionView {
let cell = self.productMenuCollectionView.cellForItem(at: indexPath) as! ProductMenuCollectionViewCell
cell.label.textColor = CustomColor.primary
} else {
}
}

Answer 1

You are observing this behaviour because the cells are reused, so one cell can be used for one index path, but when that index path scrolls out of view, and new index paths scrolls into view, the same cell object could be used for one of the new cells. Whenever you dequeue a cell, keep in mind that you might be reconfiguring old cells!
So what happens is, one of the old selected cells moves out of view, and gets reconfigured for use at a new index path. Your code presumably removes the selected color from that cell at that time, so when you scroll back up, the color is gone.
What you should do is, in ProductMenuCollectionViewCell, override isSelected:
override var isSelected: Bool {
didSet {
if isSelected {
self.label.textColor = CustomColor.primary
} else {
self.label.textColor = UIColor.black
}
}
}
And in cellForItemAtIndexPath:
if collectionView.indexPathsForSelectedItems?.contains(indexPath) ?? false {
cell.isSelected = true
} else {
cell.isSelected = false
}