UIcollectionView 单元格设置 ZIndex 。我想使用 UICollectionView 创建卡片单元答案

【问题标题】：UIcollectionView Cell set ZIndex . I want to create Card Cell using UICollectionViewUIcollectionView 单元格设置 ZIndex 。我想使用 UICollectionView 创建卡片单元
【发布时间】：2018-05-14 13:33:53
【问题描述】：

斯威夫特我正在尝试创建卡片样式的单元格。所以我正在使用集合视图并将minimumLineSpacingForSectionAt 设置为负值，此代码正在运行，看起来不错。

问题是当我有一个从底部到顶部的滚动条时，第一个单元格是顶部，但我不需要在顶部，我已附上我的代码，请检查。滚动问题后我已附加 错误图像

class SecondViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {

    let kItemSpace: CGFloat = -60.0

     @IBOutlet weak var collection_setting: UICollectionView!
     @IBOutlet var btn_top: UIButton!

     var ary: NSMutableArray = NSMutableArray()

      var ary_show: NSMutableArray = NSMutableArray()

    override func viewDidLoad() {
        super.viewDidLoad()
          ary = ["1","2","3","4","5","6","7","8","9","10","11","12","13","14","15"]

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    //-----------------------------------------------------------------------------------
    // MARK: - collection DataSource & Delegate
    //-----------------------------------------------------------------------------------



    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

        return self.ary.count



    }

    // make a cell for each cell index path
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "smallCollectionViewCell", for: indexPath as IndexPath) as! smallCollectionViewCell

            cell.inner_view.dropShadow()
            cell.inner_view.backgroundColor = .random()
           cell.layer.zPosition = -1
            cell.lbl_.text = "DEMO - \(indexPath.row)"
        //cell.bringSubview(toFront: collectionView)
        return cell
    }
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

            return CGSize(width: collectionView.frame.size.width, height: 100 )



    }
    public func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
    {



    }



    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: NSInteger) -> CGFloat {
        return kItemSpace
    }


    func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
        print(indexPath.row)

        if(indexPath.row == 14)
        {
            print("--------------->",indexPath.row)
            cell.layer.zPosition = 0
        }else
        {
            cell.layer.zPosition = -1
        }

    }







}

Demo-7,Demo-8, Demo-9 看起来不错，但其他的没有按我的意愿显示。这是第一次看起来正确。滚动后出现此问题。

【问题讨论】：

请检查此网址。 cocoacontrols.com/controls/cards-collectionview-layout
或者这个cocoacontrols.com/controls/hfcardcollectionviewlayout
这在目标 c 中也可用 cocoacontrols.com/controls/stickyflowlayout
cards-collectionview-layout 很好。但我已经完成了 90%，我只需要一个 zindex 问题解决方案。而且我无法找到解决方案。
请给我解决方案请

标签： swift uicollectionview cell

【解决方案1】：

请试试这个代码。

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

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "smallCollectionViewCell", for: indexPath as IndexPath) as! smallCollectionViewCell
    if cell == nil {
        cell.inner_view.dropShadow()
        cell.inner_view.backgroundColor = .random()
     }
       cell.layer.zPosition = -1
        cell.lbl_.text = "DEMO - \(indexPath.row)"
    return cell
}

【讨论】：

【解决方案2】：

cell.layer.zPosition = CGFloat(array.count - indexPath.row)

【讨论】：