饮料案例:

饮料类（父类）：

    public class Drink
    {
        //虚方法
        public virtual void Driking() {
        }
    }

可乐类（继承父类饮料类）

    public class Cola:Drink
    {
        //重写父类的Driking()方法
        public override void Driking()
        {
            Console.WriteLine("Cola");
        }
    }

雪碧类（继承父类饮料类）

    public class Sprite:Drink
    {
        //重写父类的Driking()方法
        public override void Driking()
        {
            Console.WriteLine("Sprite");
        }
    }

饮料工厂类（factory）

    class DrinkFactory
    {
        public static Drink Init(string type) {
            Drink drink = null;
            switch(type){
                case "可乐":
                    drink = new Cola();
                    break;
                case "雪碧":
                    drink = new Sprite();
                    break;
            }
            return drink;
        }
    }

Main方法

  class Program     {      

   static void Main(string[] args)         {       

      Console.WriteLine("请输入你要喝的饮料");        

     string type=Console.ReadLine();        

     Drink drink=DrinkFactory.Init(type);      

       drink.Driking();

     Console.ReadKey();      

   }    

}

简单工厂模式（详细）（举例饮料）