我们需要将 UIScene(实际上是一个 UIWindowScene)分配给 Window 的 WindowScene 属性，因此改进 SceneDelegate.WillConnect 中的代码如下:

We need to assign the UIScene (actually a UIWindowScene) to the WindowScene property of the Window , so improve the code in SceneDelegate.WillConnect like following :

Window = new UIWindow(scene as UIWindowScene);


UIViewController vc = new MyTabController();
Window.RootViewController = vc;

Window.MakeKeyAndVisible();