/*

​

http://stackoverflow.com/questions/1062102/practical-usage-of-virtual-functions-in-c-sharp

​

Basically virtual members allow you to express polymorphism, a derived class can have a method with the same signature as the method in its base class, and the base class will call the derived class's method.

​

*/

​

using System;

​

public class Program

{

    public class Shape

    {

        // A few example members

        public int X { get; private set; }

        public int Y { get; private set; }

        public int Height { get; set; }

        public int Width { get; set; }

​

        // Virtual method

        public virtual void Draw()

        {

            Console.WriteLine("Performing base class drawing tasks");

        }

    }

​

    class Circle : Shape

    {

        public override void Draw()

        {

            // Code to draw a circle...

            Console.WriteLine("Drawing a circle");

            base.Draw();

        }

    }

​

    class Rectangle : Shape

    {

        public override void Draw()

        {

            // Code to draw a rectangle...

            Console.WriteLine("Drawing a rectangle");

            base.Draw();

        }

    }

​

    class Triangle : Shape

    {

        public override void Draw()

        {

            // Code to draw a triangle...

            Console.WriteLine("Drawing a triangle");

            base.Draw();

        }

    }

​

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Shape s = new Shape();

        // Console.WriteLine("Shape:");

        s.Draw();

        Rectangle r = new Rectangle();

        r.Draw();

        Triangle t = new Triangle();

        t.Draw();

    }

​

​

}