private static SuanFa GetSuanFaByNumberAndOpt(string opt, int num1, int num2) { SuanFa sf = null; //判断符号 switch (opt) { case "+": sf = new Add(num1, num2); break; case "-": sf = new Sub(num1, num2); break; } return(sf); }
static void Main(string[] args) { Console.WriteLine("请您输入第一个数字"); int num1 = Convert.ToInt32(Console.ReadLine());//异常处理 Console.WriteLine("请输入第二个数字"); int num2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("请输入运算符+-*/"); string opt = Console.ReadLine(); SuanFa sf = GetSuanFaByNumberAndOpt(opt, num1, num2); if (sf != null) { Console.WriteLine(sf.Result()); Console.ReadKey(); } }