无法推送到导航控制器

Question

 override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    // 1: try loading the "Detail" view controller and typecasting it to be DetailViewController
    if let vc = storyboard?.instantiateViewController(withIdentifier: "Detail") as? DetailViewController {
        // 2: success! Set its selectedImage property
        vc.selectedImage = pictures[indexPath.row]

        // 3: now push it onto the navigation controller
        navigationController?.pushViewController(vc, animated: true)
    }
}

我面临问题-1.从“ UIViewController”投射？无关类型'DetailViewController'总是失败2.无法将类型“ DetailViewController”的值转换为预期的参数类型“ UIViewController”

Answer 1

似乎DetailViewController不是UIViewController的子类。要解决此问题，请按如下所示修改DetailViewController定义：

class DetailViewController: UIViewController {

Answer 2

还有另一种方法：将tableView单元格中的序列添加到情节提要上的视图控制器中

然后以这种方式在prepare(for segue)方法中配置detailViewController：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let vc = segue.destination as? DetailViewController {
        vc.selectedImage = pictures[indexPath.row]
    }
}