UICollectionView自定义单元格未显示

Question

I have a UICollectionView that contains custom UICollectionViewCell 's, here is the relevant code:

class customCell: UICollectionViewCell{
     var imgView = UIImageView()
     override init(frame: CGRect) {
         super.init(frame: frame)
         commonInit()
     }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    func commonInit(){
         imgView.translatesAutoresizingMaskIntoConstraints = false
         self.addcontentView.addSubview(imgView)
         //add constraints
    }
}


class CollectionViewController: UICollectionViewController {
     private let imageLib = [...] //image file name strings

     override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell : IconCollectionViewCell = collectionView.dequeueReusableCellWithReuseIdentifier(keyIconCellReuse , forIndexPath: indexPath) as! IconCollectionViewCell

        let image1 = (UIImage(named: imageLib[indexPath.row])?.imageWithRenderingMode(.AlwaysTemplate))!
        cell.imgView = UIImageView(image: image1)
        cell.imgView.tintColor = UIColor(white:0, alpha:0.7)
        cell.userInteractionEnabled = true

        return cell

    }

}

This is what it looks like now:

Answer 1

It looks like cell.setup(imageLib[indexPath.row]) adds a new UIImageView with the new image instead of reusing a existing one in the snipped code parts.

Please make sure to not initialize any views within collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) for performance reasons. Just assign the appropriate image to the imageView that belongs to the cell.

Note that cells get reused a lot by a collection view.

Edit :

With the updated question, you are doing

    let image1 = (UIImage(named: imageLib[indexPath.row])?.imageWithRenderingMode(.AlwaysTemplate))!
    cell.imgView = UIImageView(image: image1)
    cell.imgView.tintColor = UIColor(white:0, alpha:0.7)
    cell.userInteractionEnabled = true

Just

let image1 = (UIImage(named: imageLib[indexPath.row])?.imageWithRenderingMode(.AlwaysTemplate))!
cell.imgView.image = image1

and do as much other setup as possible in commonInit() .