Question

我在表格视图单元格中遇到问题图像从Google Firebase下载，每个单元格中都有一个但是，当我向上或向下滚动图像时，会自动更改索引这是我的代码，有人可以帮助我吗？非常感谢！

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if postsArray[indexPath.row].imageNoImage == true{

        let cell = tableView.dequeueReusableCell(withIdentifier: "imageLook", for: indexPath) as! imageLookTableViewCell
        cell.authorLabel.text = self.postsArray[indexPath.row].author
        cell.likesCountLabel.text = "\(self.postsArray[indexPath.row].likes!)"
        cell.postID = postsArray[indexPath.row].postId
        cell.textViewPost.text = self.postsArray[indexPath.row].textPost
        let url = URL(string: postsArray[indexPath.row].pathToImage as! String)
        if url != nil {
            DispatchQueue.global().async {
                let data = try? Data(contentsOf: url!)
                DispatchQueue.main.async {
                    if data != nil {
                        cell.imagePost.image = UIImage(data:data!)
                    }else{

                    }
                }
            }
        }
        for person in self.postsArray[indexPath.row].peopleWhoLike {
            if person == FIRAuth.auth()!.currentUser!.uid {
                cell.likesBtn.isHidden = false
                break
            }
        }

        return cell
    }

Answer 1

您的问题不是很具描述性/写得很好，但我认为您的问题是您没有缓存图像。

试试这个：

    let imageCache = NSCache()
    let cell = tableView.dequeueReusableCell(withIdentifier: "imageLook", for: indexPath) as! imageLookTableViewCell
    cell.authorLabel.text = self.postsArray[indexPath.row].author
    cell.likesCountLabel.text = "\(self.postsArray[indexPath.row].likes!)"
    cell.postID = postsArray[indexPath.row].postId
    cell.textViewPost.text = self.postsArray[indexPath.row].textPost
    let url = URL(string: postsArray[indexPath.row].pathToImage as! String)

    if url != nil {
        if let cachedImage = imageCache.objectForKey(url) as? UIImage {
            cell.imagePost.image = cachedImage
            return
        }
        DispatchQueue.global().async {
            let data = try? Data(contentsOf: url!)
            DispatchQueue.main.async {
                if data != nil {
                    if let myImageName = UIImage(data:data!){
                        imageCache.setObject(myImageName, forKey: url)
                    }
                    cell.imagePost.image = UIImage(data:data!)
                }else{

                }
            }
        }
    }
    for person in self.postsArray[indexPath.row].peopleWhoLike {
        if person == FIRAuth.auth()!.currentUser!.uid {
            cell.likesBtn.isHidden = false
            break
        }
    }

    return cell
}

表视图中的图像

1 个答案: