using System;

public class Program

{

    public static void Main()

    {

        var c = new myClass();

        writeStuff(c);

    }

    public static void writeStuff(baseClass b)

    {

        b.MyMethod();

    }

​

}

​

    public class baseClass

    {

        public bool displayTrue;

        public baseClass()

        {

            displayTrue = true;

        }

        public virtual void MyMethod()

        {

​

            if(displayTrue)

            {

                Console.WriteLine("baseClass : true");

            }

            else

            {

                Console.WriteLine("baseClass : false");

            }

        }

    }

    public class myClass : baseClass

    {   

        public myClass()

        {

            displayTrue = false;

        }

        public override void MyMethod()

        {

            if(displayTrue)

            {

                Console.WriteLine("myClass : true");

            }

            else

            {

                Console.WriteLine("myClass : false");

            }

        }

    }