rootViewController 是黑色的,不显示任何内容

rootViewController is black and shows no content

我的第一个 VC 调用 StartViewController 在启动时只是黑色(应该是黄色)。谁能帮帮我??

这是我的 AppDelegate:

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

  var window: UIWindow?

  func application(_ application: UIApplication,
                   didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    window = UIWindow(frame: UIScreen.main.bounds)
    window?.makeKeyAndVisible()

    //MARK: Start VC
    let navController = UINavigationController(rootViewController: StartViewController())
    navController.navigationBar.isTranslucent = false
    window?.rootViewController = navController
    window?.isOpaque = true
    return true
  }
}

这是我的 StartViewController Class:

import UIKit 
class StartViewController: UIViewController {
    @IBOutlet weak var btn: UIButton!    
    override func viewDidLoad() {
        super.viewDidLoad()
        print("HELLO WORLD")
    }
}

这是我的 Storyboard 的样子(之后添加):

感谢您的帮助!如果您需要查看其他 类 或内容,请询问! :)

您无法初始化像 StartViewController() 这样的故事板中的视图控制器。所以这不起作用:

let navController = UINavigationController(rootViewController: StartViewController())

相反,您需要使用 instantiateViewController 方法。确保还为您的视图控制器在情节提要中设置了“情节提要 ID”。

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewControllerID")
let navController = UINavigationController(rootViewController: viewController)