ios - 如何修复条件绑定(bind)的初始化程序必须具有可选类型，而不是 'String' ？

Question

如何解决这个问题？ 条件绑定(bind)的初始化程序必须具有可选类型，而不是“String”

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! TableViewCell

    cell.lblNamnEfternamn.text = personsArray[indexPath.row].wholeName
    cell.lblEmail.text = personsArray[indexPath.row].email
    cell.imageAvatar.image = UIImage(named: "avatar")

    if let newProfileImageUrl = personsArray[indexPath.row].profileImageUrl {
        let url = NSURL(string: newProfileImageUrl)
        let request = URLRequest(url: url! as URL)
        let task = URLSession.shared.dataTask(with: request as URLRequest) { (data, response, error) in
            if error != nil {
                print(error!)
                return
            }

            DispatchQueue.main.async {
                cell.imageAvatar.image = UIImage(data: data!)
                tableView.reloadData()
            }

        }
    }
    return cell
}

Answer 1

替换这个

if let newProfileImageUrl = personsArray[indexPath.row].profileImageUrl {

与

let newProfileImageUrl = personsArray[indexPath.row].profileImageUrl 

此外，最好使用 SDWebImage

cell.imageAvatar.sd_setImage(with: URL(string:newProfileImageUrl), placeholderImage: UIImage(named: "placeholder.png"))

而不是每次滚动时重复获取图像