如何从项目的集合视图访问选定的单元格？//项目存储的防火墙

我连接我的快速应用程序与防火墙，现在我试图从收集视图中获取选定项目的项目键，以存储选定的项目到购物车。[Firebase`import UIKit导入Firebase导入Firebase数据库导入SDWebImage类ViewController 6：UIViewController，UICollectionViewDataSource，UICollectionViewDelegate{

@IBOutlet weak var nextButton: UIButton!


@IBOutlet weak var itemCollectionView: UICollectionView!
var customItemFlowLayout: CustomItemFlowLayout!
var items = [itemsL]()
//var ind = 0


var dbRef: DatabaseReference!

override func viewDidLoad() {
    super.viewDidLoad()
    nextButton.layer.cornerRadius = 10

    dbRef = Database.database().reference().child("items")
    loadDB()

    customItemFlowLayout = CustomItemFlowLayout()
    itemCollectionView.collectionViewLayout = customItemFlowLayout
    //itemCollectionView.backgroundColor = .white

}

  func loadDB(){
    dbRef.observe(DataEventType.value, with: { (snapshot) in
        var newItems = [itemsL]()


        for itemsLSnapshot in snapshot.children {
            // condition for filtring items
            if itemsL.init(snapshot:  itemsLSnapshot as! DataSnapshot).key >= "2"{


                // bring item
                // #######
            let itemsLObject = itemsL(snapshot: itemsLSnapshot as! DataSnapshot)
            newItems.append(itemsLObject)
                // #######
            }

        }
        self.items = newItems
        self.itemCollectionView.reloadData()
    })
  }

  func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
      return items.count
  }

  func collectionView(_ collectionView: UICollectionView, cellForItemAt IndexPath: IndexPath) -> UICollectionViewCell {
      let cell = itemCollectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: IndexPath) as! ItemCollectionViewCell

      let item = items[IndexPath.row]

        cell.imageView.sd_setImage(with: URL(string: item.url),placeholderImage: UIImage(named: "image22"))
        cell.itemName.text = item.itemName
        cell.price.text = item.price

        cell.layer.borderColor = UIColor.gray.cgColor
        cell.layer.borderWidth = 1

      return cell
  }

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.layer.borderColor = UIColor.blue.cgColor
    cell?.layer.borderWidth = 3
    cell?.isSelected = true
    }


func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.layer.borderColor = UIColor.gray.cgColor
    cell?.layer.borderWidth = 1
    cell?.isSelected = false
}

}`]1