GTK (GTK#) Window created event?

Question

Is there an event equivalent to WinForm's Load, that is called when the GUI window is actually created (not the constructor)? I am using GTK# and this library has no documentation and it is quite different from plain GTK, so it is hard for me to get information from the plain GTK documentation. I tried to guess the event by trying the following code but none of them worked.

    protected override void OnRealized()
    {
        base.OnRealized();
        Debug.WriteLine("realsed");
    }

    protected override void OnActivate()
    {
        base.OnActivate();
        Debug.WriteLine("act");
    }

    protected override void OnShown()
    {
        base.OnShown();
        Debug.WriteLine("shown");
    }

    protected override void OnStateChanged(StateType previous_state)
    {
        base.OnStateChanged(previous_state);
        Debug.WriteLine("state");
    }

    protected override bool OnDrawn(Context cr)
    {
        return base.OnDrawn(cr);
        Debug.WriteLine("drawn");
    }

    protected override bool OnWindowStateEvent(EventWindowState evnt)
    {
        Debug.WriteLine("win state");
        return base.OnWindowStateEvent(evnt);
    }

    protected override void OnScreenChanged(Screen previous_screen)
    {
        base.OnScreenChanged(previous_screen);
        Debug.WriteLine("screen");
    }