以下为C#代码

以下代码用简单工厂模式实现对两个数的操作方法（计算器）

namespace 简单工厂模式
{
class Program
{
    static void Main(string[] args)
    {
         //使用方法
        Operation operation = OperationFactory.CreateOperation("+");
        operation.param1 = 2;
        operation.param2 = 4;
        Console.WriteLine(operation.GetResult());
        Console.ReadKey();
    }

    /// <summary>
    /// 操作类的父类
    /// </summary>
    public abstract class Operation
    {
        public double param1 { get; set; }
        public double param2 { get; set; }
        public abstract  double GetResult();
       
    }

    //加法
    public class AddOperation:Operation
    {
        public override double GetResult()
        {
            return param1 + param2;
        }
    }
    //减法
    public class MinusOperation:Operation
    {
        public override double GetResult()
        {
            return param1 - param2;
        }
    }
    //乘法
    public class MulOperation:Operation
    {
        public override double GetResult()
        {
            return param1 * param2;
        }
    }
    //除法
    public class DelOperation:Operation
    {
        public override double GetResult()
        {
           if(param2==0)
           {
               throw new Exception("除数不能为0");
           }
           return param1 / param2;
        }
    }
    //工厂类，用来管理所有的操作,并能向外提供访问方法
    public class OperationFactory
    {
        //根据操作符去创建对应的类
        public static Operation CreateOperation(string operationName)
        {
            Operation operation = null;
            switch(operationName)
            {
                case "+":
                    operation = new AddOperation();
                    break;
                case "-":
                    operation = new MinusOperation();
                    break;
                case "*":
                    operation = new MulOperation();
                    break;
                case "/":
                    operation = new DelOperation();
                    break;
            }
            return operation;
        }
    }
}

}