ViewController not loading from different project

Issue

In my solution, I have one iOS project that supports both iPads and iPhones. I would like to split it to have

• iOS shared project (shared views and services for both iPads and iPhones)
• iPad project with reference to the shared one
• iPhone project with reference to the shared one

I had troubles doing that, so

1. I created an empty Xamarin.iOS (for iPhone/iPad) project (with Visual Studio template) and added Class Library project (for shared logic)
2. I've added a needed reference.
3. Created TestViewController in Library project (simple one with a label only). No storyboard behind it. Just

public class TestViewController : UIViewController
{
    public TestViewController()
    {
    }

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();

        this.View.BackgroundColor = UIColor.Cyan;

        var label = new UILabel
        {
            TranslatesAutoresizingMaskIntoConstraints = false,
            Text = "Love Santa Claus"
        };
        View.Add(label);

        label.CenterXAnchor.ConstraintEqualTo(View.CenterXAnchor).Active = true;
        label.CenterYAnchor.ConstraintEqualTo(View.CenterYAnchor).Active = true;
    }
}

4. Navigate to that ViewController in AppDelegate

the problem is that the app gets stuck on the LaunchScreen. I put break point in line mainNavController.PushViewController(new TestViewController(), true);. Then TestViewController constructor is called but ViewDidLoad is not getting called in TestViewController.

I'm looking for ideas about what did I miss.

Solution

If you want to set TestViewController as the first view controller, you could set as follows:

...
UINavigationController navigationController = new UINavigationController(new TestViewController());
Window.RootViewController = navigationController;
...

in Appdelegate

the following code will work before iOS 13.0

public bool FinishedLaunching (UIApplication application, NSDictionary launchOptions)
{
   // Override point for customization after application launch.
   // If not required for your application you can safely delete this method

   this.Window = new UIWindow(UIScreen.MainScreen.Bounds);
   UINavigationController navigationController = new UINavigationController(new TestViewController());
   this.Window.RootViewController = navigationController ;
   this.Window.MakeKeyAndVisible();

   return true;
}

And after iOS 13.0 , we should call the similar code in SceneDelegate , so add the following code to SceneDelegate at same time .

public void WillConnect (UIScene scene, UISceneSession session, UISceneConnectionOptions connectionOptions)
{
    // 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.Window = new UIWindow(new UIWindowScene(session,connectionOptions));
    UINavigationController navigationController = new UINavigationController(new TestViewController());
    this.Window.RootViewController = navigationController;
    this.Window.MakeKeyAndVisible();

    // This delegate does not imply the connecting scene or session are new (see  UIApplicationDelegate `GetConfiguration` instead).
}

Answered By - Junior Jiang