设计模式实例-工厂方法模式

using System;
namespace Ahoo.Demo.DesignPatterns.Patterns.FactoryMethod
{
    /*######工厂方法模式####### * 定义一个用于创建对象的接口， * 让子类觉得实例化哪个类。 * 使类的实例化延迟到子类 */

    #region 操作类
    /// <summary>
    /// 抽象类
    /// </summary>
    public abstract class Operation
    {
        public double FirstNumber { get; set; }
        public double SecondNumber { get; set; }
        public abstract double GetResult();
    }

    public class AddOperation : Operation
    {
        public override double GetResult()
        {
            double result = FirstNumber + SecondNumber;
            return result;
        }
    }
    /// <summary>
    /// 具体操作子类(-)
    /// </summary>
    public class SubOperation : Operation
    {
        public override double GetResult()
        {
            double result = FirstNumber - SecondNumber;
            return result;
        }
    }
    /// <summary>
    /// 具体操作子类(*)
    /// </summary>
    public class MulOperation : Operation
    {
        public override double GetResult()
        {
            double result = FirstNumber * SecondNumber;
            return result;
        }
    }
    /// <summary>
    /// 具体操作子类(/)
    /// </summary>
    public class DivOperation : Operation
    {
        public override double GetResult()
        {
            if (SecondNumber == 0)
            {
                throw new ArgumentException("参数[SecondNumber]不能为0！");
            }
            double result = FirstNumber / SecondNumber;
            return result;
        }
    }
    #endregion

    /// <summary>
    /// 工厂接口
    /// </summary>
    interface IFactory
    {
        Operation CreateOperation();
    }

    public class AddFactory : IFactory
    {
        public Operation CreateOperation()
        {
            return new AddOperation();
        }
    }
    public class SubFactory : IFactory
    {
        public Operation CreateOperation()
        {
            return new SubOperation();
        }
    }
    public class AddFactory : IFactory
    {
        public Operation CreateOperation()
        {
            return new AddOperation();
        }
    }
    public class MulFactory : IFactory
    {
        public Operation CreateOperation()
        {
            return new MulOperation();
        }
    }
    public class DivFactory : IFactory
    {
        public Operation CreateOperation()
        {
            return new DivOperation();
        }
    }

    public class Client
    {
        public static void Excute()
        {
            IFactory factory = new AddFactory();
            Operation operation = factory.CreateOperation();

            Console.WriteLine("请输入操作符 第一个操作数");
            operation.FirstNumber = Double.Parse(Console.ReadLine());
            Console.WriteLine("请输入操作符 第二个操作数");
            operation.SecondNumber = Double.Parse(Console.ReadLine());
            Console.WriteLine("结果为：{0}", operation.GetResult());
        }
    }
}