问在UICollectionViewCell中实现UIStackView

EN

import UIKit

class CollectionCell: UICollectionViewCell {

    @IBOutlet var ratingView: UIStackView!

    var rating : Float!
    {
       didSet {
           self.ratingView.addArrangedSubview(addRating())
      }
    }

    func addRating() -> UIStackView
    {
      let stackView = UIStackView()
      stackView.axis = .horizontal

      let oneStarImage = UIImage(named: "full_star")
      let halfStarImage = UIImage(named: "half_star")

      //hard coded        
      var value = 1.0

      while true {
        value -= 1
        if value >= 0 {
            print("Add 1 star")
            let imageView = UIImageView()
            imageView.image = oneStarImage
            stackView.addArrangedSubview(imageView)

        } else if value == -0.5 {
            print("Add half a star")
            let imageView = UIImageView()
            imageView.image = halfStarImage
            stackView.addArrangedSubview(imageView)
            break
        }
        else {
            break
        }
     }
     return stackView
   }
 }

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath) as! CollectionViewCell
    cell.rating = 1.0
    return cell
}