浅析.net简单工厂模式

     public class Sub : Calculator
     {
         public override double GetResult()
         {
             return NumberA + NumberB;
         }
     }
     /// <summary>
     /// 计算器工厂
     /// </summary>
     public class CalculatorFactory
     {
         public static Calculator GetResult(string oper)
         {
             Calculator calcu = null;
             switch (oper)
             {
                 case "+":
                     calcu = new Add();
                     break;
                 case "-":
                     calcu = new Sub();
                     break;
             }
             return calcu;
         }
     }
 }

  static void Main(string[] args)
         {
             Console.WriteLine("请输入数字A：");
             string numbera = Console.ReadLine();
             Console.WriteLine("请输入运算符：");
             string oper = Console.ReadLine();
             Console.WriteLine("请输入数字B：");
             string numberb = Console.ReadLine();
             Calculator c = CalculatorFactory.GetResult(oper);