hhc:
            Console.WriteLine("1进入xx 2进入xxx 3退出 ");
                int i = int.Parse(Console.ReadLine().ToString());
                switch (i)
                {
                    case 1:
                        Console.WriteLine("你好");
                        goto hhc;
                       
                    case 2:
                        Console.WriteLine("大家好");
                        break;                }