WPF Window created in Application_Startup method is blank

Question

I have a WPF window in a project with a XAML file and associated C# code behind file. If I set "StartupUri=MainWindow.xaml" in App.xaml to this window the window opens as expected when I start my application.

However, I want my application to to take command line parameters and then decided if it should open the GUI or not. So instead I've set "Startup=Application_Startup" in my App.xaml file which is defined as shown below.

    private void Application_Startup(object sender, StartupEventArgs e)
    {
        if (e.Args.Length > 1)
        {
            //do automated tasks
        }
        else
        {
            //open ui

           MainWindow window = new MainWindow();
            this.MainWindow = window;

            window.Show();
        }
    }

Yet when I run this the window displayed is totally blank.

Answer 1

Adding window.InitializeComponent() seems to do the trick:

            MainWindow window = new MainWindow();
            Application.Current.MainWindow = window;
            window.InitializeComponent();
            window.Show();

I usually like to have a little explanation on why something does or doesn't work. I have no clue in this case. I can see that the examples online don't include InitializeComponent, and yet I produce the same exact error as you do (event without checking for args).