为什么我的简单SWIFT简单视图为黑色？

问题描述

我对SWIFT相当陌生。我想从头开始创建视图。我只是想显示一个标签。但是，在模拟器中，我只是看到黑屏。这是我的SceneDelegate文件：

import UIKit

class SceneDelegate: UIResponder,UIWindowSceneDelegate {

    var window: UIWindow?


    func scene(_ scene: UIScene,willConnectTo session: UISceneSession,options connectionOptions: UIScene.ConnectionOptions) {
        
        print("start?")
        
        window = UIWindow()
        window?.makeKeyAndVisible()
        
        let gameViewController = ViewController()
        window?.rootViewController = gameViewController
        // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
        // If using a storyboard,the `window` property will automatically be initialized and attached to the scene.
        // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
        guard let _ = (scene as? UIWindowScene) else { return }
    }

    func sceneDidDisconnect(_ scene: UIScene) {
        // Called as the scene is being released by the system.
        // This occurs shortly after the scene enters the background,or when its session is discarded.
        // Release any resources associated with this scene that can be re-created the next time the scene connects.
        // The scene may re-connect later,as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Called when the scene has moved from an inactive state to an active state.
        // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
    }

    func sceneWillResignActive(_ scene: UIScene) {
        // Called when the scene will move from an active state to an inactive state.
        // This may occur due to temporary interruptions (ex. an incoming phone call).
    }

    func sceneWillEnterForeground(_ scene: UIScene) {
        // Called as the scene transitions from the background to the foreground.
        // Use this method to undo the changes made on entering the background.
    }

    func sceneDidEnterBackground(_ scene: UIScene) {
        // Called as the scene transitions from the foreground to the background.
        // Use this method to save data,release shared resources,and store enough scene-specific state information
        // to restore the scene back to its current state.
    }


}

这是我的视图控制器文件：

import UIKit

class ViewController: UIViewController {
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    let label = UILabel(frame: CGRect(x: 0,y: 0,width: 200,height: 21))
    label.center = CGPoint(x: 160,y: 284)
    label.textAlignment = NSTextAlignment.center
    label.text = "I'm a test label"
    self.view.addSubview(label)
    
    print("test")
}


}

我看到调试器打印了

start?
test

任何见解或技巧都将不胜感激，谢谢

解决方法

尝试将场景传递到窗口，window = UIWindow（windowScene：scene）

,

window应该以{{1​​}}作为参数进行初始化。

windowScene