Question

我有一个收集视图，该收集视图基于从firebase中获取的内容填充了视频或图像。

我遇到了一个问题，当我获取数据并将其添加到单元格时，某些单元格会在[图像的顶部]添加视频。

我仔细检查了下面的代码，似乎无法。找到问题的根源。

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

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "p1Item", for: indexPath) as! CollectionViewCell1

    if postArray[indexPath.item].media[0].image != nil { //its an image

        let date = ConvertDate(mediaTimestamp: postArray[indexPath.row].media[0].postNum!, isItForP3: false).getDate!

        do {                
            cell.imageView.image = postArray[indexPath.item].media[0].image!

            if postArray[indexPath.item].user.profileImageUrl != "" {
                let url = URL(string: "\(postArray[indexPath.item].user.profileImageUrl)")
                let data = try Data(contentsOf: url!)

                if let profileImage = UIImage(data: data) {
                    cell.profImage.image = profileImage
                    cell.titleLabel.text = postArray[indexPath.item].user.username
                    cell.subtitleLabel.text = date
                }
            } else {
                //I add a fake image here
                cell.titleLabel.text = postArray[indexPath.item].user.username
                cell.subtitleLabel.text = date
                cell.profImage.image = UIImage(named: "media")
            }

        } catch {
            print("need to add stuff to this catch")
        }

    } else { //its a video

        let videoURL = postArray[indexPath.item].media[0].videoURL

        let player = AVPlayer(url: videoURL! as URL)
        let playerLayer = AVPlayerLayer(player: player)
        playerLayer.frame = cell.bounds
        cell.layer.addSublayer(playerLayer)

        let date = ConvertDate(mediaTimestamp: postArray[indexPath.item].media[0].postNum!, isItForP3: false).getDate!

        do {
            if postArray[indexPath.item].user.profileImageUrl != "" {
                let url = URL(string: "\(postArray[indexPath.item].user.profileImageUrl)")
                let data = try Data(contentsOf: url!)
                if let profileImage = UIImage(data: data) {
                    cell.profImage.image = profileImage
                    cell.titleLabel.text = postArray[indexPath.item].user.username
                    cell.subtitleLabel.text = date
                }
            } else {
                //I add a fake profile image here
                cell.titleLabel.text = postArray[indexPath.item].user.username
                cell.subtitleLabel.text = date
                cell.profImage.image = UIImage(named: "media")
            }
        } catch {
            print("need to add stuff to this catch")
        }
    }

    print("Completed: ", cell.imageView!)

    return cell
}

我该如何解决？

Answer 1

原因在这里

 cell.layer.addSublayer(playerLayer)

您应该清除单元格，因为它已出队

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "p1Item", for: indexPath) as! CollectionViewCell1
cell.layer.sublayers.forEach {
  if $0 is AVPlayerLayer {
    $0.removeFromSuperlayer()
  }
}

，也不要使用

 let data = try Data(contentsOf: url!)

对于远程数据抓取，您可以使用SDWebImage

Answer 2

当你说

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "p1Item", for: indexPath) as! CollectionViewCell1

这意味着您正在重用旧单元格，在这种情况下，旧单元格可能具有AVPlayerLayer

解决此问题的一种方法是使用不同的withReuseIdentifier

if postArray[indexPath.item].media[0].image != nil { //its an image
       let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ImgageCell", for: indexPath) as! CollectionViewCell1

       return cell

    } else { //its a video
       let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "VideoCell", for: indexPath) as! CollectionViewCell1

       return cell   
    }
}

或者在重用之前重置单元，即在dequeueReusableCell之后删除图层

在收藏夹视图中，视频是否放置在图像顶部？

2 个答案: