1: public interface IAnimal

   2: {

   3:    void makeSound();

   4: }

   1: public class Dog : IAnimal

   2: {

   3:    public void makeSound()

   4:    {

   5:        Console.WriteLine("Dog is barking!");

   6:    }

   7: }

   1: public class Cat : IAnimal

   2: {

   3:     public void makeSound()

   4:     {

   5:         Console.WriteLine("Cat can meow!");

   6:     }

   7: }

   1: public class Duck : IAnimal

   2: {

   3:     public void makeSound()

   4:     {

   5:         Console.WriteLine("Duck just quack!");

   6:     }

   7: }

   1: public static class SimpleAnimalFactory

   2: {

   3:    private static Dictionary<string, IAnimal> animals = new Dictionary<string, IAnimal>();

   4:    public static IAnimal CreateAnimal(string Name)

   5:    {

   6:        if (animals.Count == 0)

   7:        {

   8:            animals.Add("Cat", new Cat());

   9:            animals.Add("Dog", new Dog());

  10:            animals.Add("Duck", new Duck());

  11:        }

  12:        return animals[Name];

  13:    }

  14: }

   1: static void Main(string[] args)

   2: {

   3:     SimpleAnimalFactory.CreateAnimal("Cat").makeSound();

   4:     SimpleAnimalFactory.CreateAnimal("Dog").makeSound();

   5:     SimpleAnimalFactory.CreateAnimal("Duck").makeSound();

   6:     Console.ReadKey();

   7: }

   1: public static class SimpleAnimalFactory

   2: {

   3:     private static Dictionary<string, IAnimal> animals = new Dictionary<string, IAnimal>();

   4:     private static IList<string> names = new List<string>();

   5:     public static IAnimal CreateAnimal(string Name)

   6:     {

   7:         if (animals.Count == 0)

   8:         {

   9:             animals.Add("Cat", new Cat());

  10:             animals.Add("Dog", new Dog());

  11:             animals.Add("Duck", new Duck());

  12:         }

  13:         return animals[Name];

  14:     }

  15:     public static IAnimal CreateAnimal(int index)

  16:     {

  17:         if (names.Count == 0)

  18:         {

  19:             names.Add("Cat");

  20:             names.Add("Dog");

  21:             names.Add("Duck");

  22:         }

  23:         string name = names[index % animals.Count];

  24:         return CreateAnimal(name);

  25:     }

  26: }

   1: public class RandomFactory : IAnimalFactory

   2: {

   3:     public IAnimal factoryMethod()

   4:     {

   5:         Random rnd = new Random(Guid.NewGuid().GetHashCode());

   6:         int index = rnd.Next(0, 1000);

   7:         return SimpleAnimalFactory.CreateAnimal(index);

   8:     }

   9: }

   1: public class BalanceFactory : IAnimalFactory

   2: {

   3:    int index = 0;

   4:    public IAnimal factoryMethod()

   5:    {

   6:        return SimpleAnimalFactory.CreateAnimal(index++);

   7:    }

   8: }

   1: static void Main(string[] args)

   2: {

   3:    SimpleAnimalFactory.CreateAnimal("Cat").makeSound();

   4:    SimpleAnimalFactory.CreateAnimal("Dog").makeSound();

   5:    SimpleAnimalFactory.CreateAnimal("Duck").makeSound();

   6:    Console.WriteLine("-------------------------");

   7:    Console.ReadKey();

   8:    //-----------------------------------------

   9:    Console.WriteLine("RandomFactory Example:");

  10:    RandomFactory randFactory = new RandomFactory();

  11:    for(int i=0; i<9;i++)

  12:    {

  13:        Console.Write("#{0}:", i);

  14:        randFactory.factoryMethod().makeSound();

  15:    }

  16:    Console.WriteLine("-------------------------");

  17:    Console.ReadKey();

  18:    //-----------------------------------------

  19:    Console.WriteLine("BalanceFactory Example:");

  20:    BalanceFactory balanceFactory = new BalanceFactory();

  21:    for (int i = 0; i < 9; i++)

  22:    {

  23:        Console.Write("#{0}:", i);

  24:        balanceFactory.factoryMethod().makeSound();

  25:    }

  26:        

  27:    Console.ReadKey();

  28: }