CollectionView高亮显示图像

Question

我在自定义UICollectionViewCell中显示4张图像作为黑白图像 图像突出显示，我想显示另一个图像但是颜色正如我在didHighlightItemAtIndexPath中尝试的那样。 我怎么能这样做，非常感谢任何建议。

如果可能，当用户释放触摸单元格时，图像会变回黑白：

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

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

    // Display the country name
    if let value = countries[indexPath.row]["nameEnglish"] as? String {
        cell.cellTitle.text = value
    }

    // Display "initial" flag image
    let initialThumbnail = UIImage(named: "question")
    cell.cellImage.image = initialThumbnail

    // Fetch final flag image - if it exists
    if let value = countries[indexPath.row]["blackWhite"] as? PFFile {
        let finalImage = countries[indexPath.row]["blackWhite"] as? PFFile
        finalImage!.getDataInBackgroundWithBlock {
            (imageData: NSData?, error: NSError?) -> Void in
            if error == nil {
                if let imageData = imageData {
                    cell.cellImage.image = UIImage(data:imageData)
                }
            }
        }
    }
    return cell



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

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

    if cell.cellImage.highlighted == true {         
        if let value = countries[indexPath.row]["flag"] as? PFFile {
            let finalImage = countries[indexPath.row]["flag"] as? PFFile
            finalImage!.getDataInBackgroundWithBlock {
                (imageData: NSData?, error: NSError?) -> Void in
                if error == nil {
                    if let imageData = imageData {
                        cell.cellImage.image = UIImage(data:imageData)

                    }
                }
            }}
      //  return cell
    }


}

或者我应该改变它：

        // Process collectionView cell selection
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

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


    if indexPath.row == 0 {
        let currentObject = countries[indexPath.row]
        self.performSegueWithIdentifier("CollectionViewToTableView", sender: currentObject)

    }

collectionViewCell

    class menuCollectionViewCell: UICollectionViewCell {

@IBOutlet var cellTitle: UILabel!

@IBOutlet var cellImage: UIImageView!


func toggleSelected ()
{
    if (selected){
        backgroundColor = UIColor.orangeColor()
    }else {
        backgroundColor = UIColor.whiteColor()
    }
}

}