C# Lesson 17 : Working with Classes and Inheritances in the .NET Framework Class Library

This lesson continues to teach concepts about classes (specifically, in this case, inheritance) by showing you how to utilize inheritance in your own custom classes. Learn about overriding virtual functionality, abstract base classes, and sealed classes. 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace UnderstandingInheritance
{
    class Program
    {
        static void Main(string[] args)
        {
            Car myCar = new Car();
            myCar.Make = "BMW";
            myCar.Model = "745li";
            myCar.Color = "Black";
            myCar.Year = 2005;
            //myCar.TowingCapacity = 1200;

            printVehicleDetails(myCar);


            Truck myTruck = new Truck();

            myTruck.Make = "Ford";
            myTruck.Model = "F950";
            myTruck.Year = 2006;
            myTruck.Color = "Black";
            myTruck.TowingCapacity = 1200;
            printVehicleDetails(myTruck);

            Console.ReadLine();
        }

        private static void printVehicleDetails(Vehicle vehicle)
        {
            Console.WriteLine("Here are the vehcile's details: {0}",
                vehicle.FormatMe());
        }

    }

    abstract class Vehicle
    {
        public string Make { get; set; }
        public string Model { get; set; }
        public int Year { get; set; }
        public string Color { get; set; }

        public abstract string FormatMe();
    }

    class Car : Vehicle
    {
        public override string FormatMe()
        {
            return String.Format("{0} - {1} - {2} - {3}",
                this.Make,
                this.Model,
                this.Color,
                this.Year);
        }
    }

    sealed class Truck : Vehicle
    {
        public int TowingCapacity { get; set; }

        public override string FormatMe()
        {
            return String.Format("{0} - {1} - {2} Towing units",
                this.Make,
                this.Model,
                this.TowingCapacity);
        }

    }

    /*
    class Semi : Truck
    {

    }
    */

}
Source : MS Virtual Academy