如何呈现 Class 故事板

Question

我以编程方式编写 UI，现在我想从情节提要中添加 ui，当我尝试这样做时，编译器说 "Unexpectedly found nil while unwrapping an Optional value"

在故事板中 -> ViewController -> 自定义 Class 我设置了我的 class。我还设置了 ID "board1" 为什么设置为零值？？？

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        table.deselectRow(at: indexPath, animated: true)
        let registerViewController = storyboard?.instantiateViewController(withIdentifier: "board1") as? RegisterViewController
        present(registerViewController!, animated: true, completion: nil)
    }

Answer 1

您可以这样做：

// Perform the segue to the viewController you want. Make sure you set the identifier the same as in the storyboard

let VC1 = (self.storyboard?.instantiateViewController(withIdentifier: "yourIdentifier"))!
self.present(VC1, animated: true, completion: nil)

也可以为此写一个扩展：

extension UIViewController {
    func presentView(withIdentifier: String) {
        if let newVC = self.storyboard?.instantiateViewController(withIdentifier: withIdentifier) {
        self.present(newVC, animated: true, completion: nil)
        }
    }
}

然后这样称呼它

self.presentView(withIdentifier: "yourIdentifier")

Answer 2

您似乎在此处使用了一些未知的 storyboard 实例：

let registerViewController = storyboard?.instantiateViewController(withIdentifier: "board1") as? RegisterViewController

根据您的评论，storyboard 似乎不是您声明的。这意味着它可能不是指您的 Main.storyboard 文件，甚至可能是 nil。

您应该创建一个引用您的 Main.storyboard 文件的新 UIStoryboard 实例，如下所示：

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let registerViewController = storyboard.instantiateViewController(withIdentifier: "board1") as? RegisterViewController

如何呈现 Class 故事板

how present Class with storyboard

storyboard

uiviewcontroller

swift