using System;

​

public class MyBase

{

    public virtual void SomeLogicThatCanBeOverrided(int x)

    {

        Console.WriteLine("MyBase: SomeLogic ");

        Console.WriteLine("Hung Chun Wai is handsome when he was {0}",x);

    }

​

    public void AnotherLogic()

    {

        Console.WriteLine("MyBase: AnotherLogic");

    }

}

​

public class Derived : MyBase

{

    // this override the MyBase method

    public override void SomeLogicThatCanBeOverrided(int x) //the overriden function should have the same case with the virtual function in the base class

    {

        Console.WriteLine("Derived: SomeLogic ");

        Console.WriteLine("Hung Chun Wai is less handsome when he was ",+x);

    }

}

​

public class Program

{

    public static void Main()

    {

        MyBase b = new MyBase();

        Derived d = new Derived();

        b.SomeLogicThatCanBeOverrided(17);

        b.AnotherLogic();

        Console.WriteLine("\n");

        //the derived class d inherit from the base class, so d can call the two functions

        d.SomeLogicThatCanBeOverrided(21);//the base functio is overriden

        d.AnotherLogic();

    }

}