Console.WriteLine("1土豆");            Console.WriteLine("2玉米");            Console.WriteLine("3小麦");            Console.WriteLine("4黄瓜");            Console.Write("请输入你选的：");            string s = Console.ReadLine();            switch (s)            {                 case "1":                    Console.WriteLine("你选择1");                    break;                case "2":                    Console.WriteLine("你选择2");                    break;                case "3":                    Console.WriteLine("你选择3");                    break;                case "4":                    Console.WriteLine("你选择4");                    break;                default:                    Console.WriteLine("选择有误！");                    break;            }