Head First设计模式之工厂模式

namespace DesignPatterns.FactoryMethod
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("使用工厂方法进行计算");
            Factory factory1 = new AddFactory();
            Operation operation1 = factory1.CreateOperation();
            operation1.numberA = 10;
            operation1.numberB = 20;
            Console.WriteLine("{0}+{1}={2}", operation1.numberA, operation1.numberB, operation1.GetResult());

            Factory factory2 = new SubFactory();
            Operation operation2 = factory2.CreateOperation();
            operation2.numberA = 10;
            operation2.numberB = 20;
            Console.WriteLine("{0}-{1}={2}", operation2.numberA, operation2.numberB, operation2.GetResult());
            Console.Read();
        }
    }

    /// <summary>
    /// 抽象操作类
    /// </summary>
    public abstract class Operation
    {
        public int numberA;
        public int numberB;
        public abstract int GetResult();
    }
    /// <summary>
    /// 加法操作
    /// </summary>
    public class AddOperation : Operation
    {
        public override int GetResult()
        {
            return (this.numberA + this.numberB);
        }
    }
    /// <summary>
    /// 减法操作
    /// </summary>
    public class SubOperation : Operation
    {
        public override int GetResult()
        {
            return (this.numberA - this.numberB);
        }
    }

    public abstract class Factory
    {
        public abstract Operation CreateOperation();
    }

    public class AddFactory : Factory
    {
        public override Operation CreateOperation()
        {
            return new AddOperation();
        }
    }

    public class SubFactory : Factory
    {
        public override Operation CreateOperation()
        {
            return new SubOperation();
        }
    }
}