test.cs

using System;
using System.Threading;

class Base {
    public Base ()
    {
        Console.WriteLine ("Base.ctor");
        ViewDidLoad ();
    }

    public virtual void ViewDidLoad ()
    {
        Console.WriteLine ("Base.ViewDidLoad");
    }
}

class Derived : Base {
    public Derived ()
    {
        Console.WriteLine ("Derived.ctor");
    }

    public override void ViewDidLoad ()
    {
        Console.WriteLine ("Derived.ViewDidLoad");
        base.ViewDidLoad ();
    }

    static void Main ()
    {
        new Derived ();
    }
}

/*
 * This prints:
Base.ctor
Derived.ViewDidLoad
Base.ViewDidLoad
Derived.ctor
 */