Unhide the selected cells' 'tick' in a collectionView - ios

Question

I have a collectionView of images and I want to show when multiple of these cells are selected.
I use a simple cell.myUIImage.isHidden = false but nothing seems to work.
Multiple select is enabled in the Interface Builder and is set in viewDidLoad(), this is what I have:
#IBOutlet weak var myUIImage: UIImageView!
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "photoItemView", for: indexPath) as! PhotoFeed
cell.myUIImage.isHidden = false
print ("cell was selected at:", indexPath.item)
photoCollection.reloadData()
}

Answer 1

You can not access UICollectionViewCell with dequeueReusableCell other than cellForItemAt indexPath method.
To access cell in didSelectItemAt indexPath use:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if let collectionCell = collectionView.cellForItem(at: indexPath) as? PhotoFeed {
collectionCell.myUIImage.isHidden = false
print ("cell was selected at:", indexPath.item)
photoCollection.reloadData()
}
}
But again photoCollection.reloadData() will reload the cell and myUIImage will be hidden again.
So you need to maintain the selected indexes and show/hide in cellForItemAt indexPath. With the help of selectedIndexes you can have the functionality like show image on selection and hide image on select again.
You should have an array of selectedIndexes. Say
var selectedIndexes = [IndexPath]()
Add in didSelectItemAt indexPath, Update method as:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if selectedIndexes.contains(indexPath) {
if let index = selectedIndexes.index(of: indexPath) {
selectedIndexes.remove(at: index)
}
} else {
selectedIndexes.append(indexPath)
}
photoCollection.reloadData()
}
In cellForItemAt indexPath:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {\
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "photoItemView", for: indexPath) as? PhotoFeed else {
fatalError("cell not found")
}
if selectedIndexes.contains(indexPath) {
cell.myUIImage.isHidden = false
} else {
cell.myUIImage.isHidden = true
}
return cell
}

Answer 2

You should create #IBOutlet for myUIImage in collectionviewcell:
class PhotoFeed: UICollectionViewCell {
#IBOutlet weak var myUIImage: UIImageView!
}
In ViewController:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "photoItemView", for: indexPath) as! PhotoFeed
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as! PhotoFeed
cell.myUIImage.isHidden = !cell.myUIImage.isHidden
}