Abstract Factory Design Pattern in C#: Real-World Example and Code Explanations

using System;
namespace AbstractFactoryExample
{ // Author: Shekh Ali

    // The 'ICarFactory' interface defines methods for creating objects
    // related to cars.
    interface ICarFactory
    {
        SportsCar CreateSportsCar();
        FamilyCar CreateFamilyCar();
    }

    // The 'SportsCar' class represents a sports car
    class SportsCar
    {
        public virtual void Drive()
        {
            Console.WriteLine("Driving a sports car");
        }
        public virtual void OpenSunRoof()
        {
            Console.WriteLine("Opening sunroof");
        }
    }

    // The 'FamilyCar' class represents a family car
    class FamilyCar
    {
        public virtual void Drive()
        {
            Console.WriteLine("Driving a family car");
        }
    }

    class MercedesSportsCar : SportsCar
    {
        public int Horsepower { get; set; }
        public int NumberOfSeats { get; set; }
        public string Color { get; set; }
        public string TransmissionType { get; set; }

        public override void OpenSunRoof()
        {
            Console.WriteLine("\n Opening sunroof of a Mercedes sports car");
        }

        public override void Drive()
        {
            Console.WriteLine($" Driving a {Color} Mercedes sports car with {Horsepower} horsepower with {NumberOfSeats} seats.");
            Console.WriteLine($" Transmission Type: {TransmissionType}");
        }
    }
    class MercedesFamilyCar : FamilyCar
    {
        public int NumberOfSeats { get; set; }
        public int NumberOfDoors { get; set; }
        public string Color { get; set; }
        public string TransmissionType { get; set; }

        public override void Drive()
        {
            Console.WriteLine("\n Driving a Mercedes family car with " + NumberOfSeats + " seats and " + NumberOfDoors + " doors.");
            Console.WriteLine($" Transmission Type: {TransmissionType}\n");
        }
    }


    class BMWSportsCar : SportsCar
    {
        // Add specific implementation for BMW sports car here
        public int Horsepower { get; set; }
        public int NumberOfSeats { get; set; }
        public string Color { get; set; }
        public string TransmissionType { get; set; }

        public override void OpenSunRoof()
        {
            Console.WriteLine("\n Opening sunroof of a BMW sports car");
        }

        public override void Drive()
        {
            Console.WriteLine($" Driving a {Color} BMW sports car with {Horsepower} horsepower with {NumberOfSeats} seats.");
            Console.WriteLine($" Transmission Type: {TransmissionType}");
        }
    }

    class BMWFamilyCar : FamilyCar
    {
        // Add specific implementation for BMW family car here
        public int NumberOfSeats { get; set; }
        public int NumberOfDoors { get; set; }
        public string Color { get; set; }
        public string TransmissionType { get; set; }

        public override void Drive()
        {
            Console.WriteLine($"\n Driving a {Color} BMW family car with {NumberOfSeats} seats and {NumberOfDoors} doors.");
            Console.WriteLine($" Transmission Type: {TransmissionType}\n");
        }
    }

    // The 'MercedesFactory' class creates objects related to Mercedes cars
    class MercedesFactory : ICarFactory
    {
        public SportsCar CreateSportsCar()
        {
            // Here, you can create an instance of the MercedesSportsCar class
            return new MercedesSportsCar()
            {
                Color = "Red",
                Horsepower = 1048,
                NumberOfSeats = 2,
                TransmissionType = "CVT transmission"
            };
        }

        public FamilyCar CreateFamilyCar()
        {
            // Here, you can create an instance of the MercedesFamilyCar class
            return new MercedesFamilyCar()
            {
                Color = "White",
                NumberOfDoors = 4,
                NumberOfSeats = 4,
                TransmissionType = "DCT transmission"
            };
        }
    }

    // The 'BMWFactory' class creates objects related to BMW cars
    class BMWFactory : ICarFactory
    {
        public SportsCar CreateSportsCar()
        {
            // Here, you can create an instance of the BMWSportsCar class
            return new BMWSportsCar()
            {
                Color = "Red",
                Horsepower = 1048,
                NumberOfSeats = 2,
                TransmissionType = "Automatic (TC)"
            };
        }

        public FamilyCar CreateFamilyCar()
        {
            // Here, you can create an instance of the BMWFamilyCar class
            return new BMWFamilyCar()
            {
                Color = "Black Sapphire Metallic",
                NumberOfDoors = 4,
                NumberOfSeats = 7,
                TransmissionType = "DCT transmission"
            };
        }
    }

    // This class represents a client that uses the factory
    class CarClient
    {
        private SportsCar _sportsCar;
        private FamilyCar _familyCar;

        public CarClient(ICarFactory factory)
        {
            _sportsCar = factory.CreateSportsCar();
            _familyCar = factory.CreateFamilyCar();
        }

        public void DriveCars()
        {
            _sportsCar.Drive();
            _familyCar.Drive();
        }
        public void OpenSunRoof()
        {
            _sportsCar.OpenSunRoof();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // The client code can work with any factory class.
            ICarFactory factory = new MercedesFactory();
            CarClient client = new CarClient(factory);
            client.OpenSunRoof();
            client.DriveCars();

            factory = new BMWFactory();
            client = new CarClient(factory);
            client.DriveCars();

            Console.ReadLine();
        }
    }
}