在Swift中的UICollectionView中更改文本颜色

Question

I have a UICollectionView with cells that contain UILabels that update dynamically. When I select a cell, I have the background color of the cell change, but I want the text color in the label to change as well. Currently, I'm using the following code:

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    cell = collectionView.dequeueReusableCellWithReuseIdentifier("targetCell", forIndexPath: indexPath) as UICollectionViewCell
    var label : UILabel = cell.viewWithTag(100) as UILabel
    label.textColor = UIColor.whiteColor()
}

However, on selecting the cell, the text color does not update with the new color. Any ideas why?

Answer 1

Because you are dequeuing a reusable cell and update it.

Basically, dequeueReusableCellWithReuseIdentifier:forIndexPath: is only used in collectionView:cellForItemAtIndexPath: .

Use cellForItemAtIndexPath to get the selected cell.

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    if let cell = collectionView.cellForItem(at: indexPath) {
        let label = cell.viewWithTag(100) as? UILabel
        label?.textColor = UIColor.white
    }
}