Collection View Cells alpha is changing when it is not supposed to

Question

I basically have a collection view where the cells have a view and that view's alpha decreases when the cell is tapped on. For some reason, when I scroll in the collection view, other cells views are also changing alphas and then the original cell that I selected also changed back. It has something to do with the cellForRowAtIndexPath method, but I'm not entirely sure what the issue is. Here is my code:

 func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("chooseSpace", forIndexPath: indexPath)as! ChooseSpaceCell

    let space = spaces2[indexPath.row]

    cell.serviceLabel.text = spaces2[indexPath.row]

    return cell
}


func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    let cell = collectionView.cellForItemAtIndexPath(indexPath) as! ChooseSpaceCell

    cell.mask.alpha = 0.7
}

func collectionView(collectionView: UICollectionView, didDeselectItemAtIndexPath indexPath: NSIndexPath) {

    let cell = collectionView.cellForItemAtIndexPath(indexPath) as! ChooseSpaceCell

    cell.mask.alpha = 0.25

}

Originally, all the alphas start out at 0.25, change to 0.7 when tapped, and change back when deselected. This is a huge issue so any help would be much appreciated.

Maintain a flag in an object for each indexpath..according to that flag change alpha.. — Rohit Pradhan, Jan 10 '16 at 03:42

score 1 · Answer 1 · answered Jan 10 '16 at 03:51

When you call

let cell = collectionView.dequeueReusableCellWithReuseIdentifier("chooseSpace", forIndexPath: indexPath)as! ChooseSpaceCell

You are requesting a cell from the collection view. If there is a cell available it will reuse a cell that has already been created. If none are available it creates a new cell.

This means that when you scroll your collection view it is reusing the same cells that you used for previous items. If those items had there opacity changed the new items using that cell will have the same opacity.

You need to add an opacity field to your model or an attribute that will help you compute the opacity.

Collection View Cells alpha is changing when it is not supposed to

1 Answers1