Console.WriteLine("请输入一个整数。");
            int a = ReadInt();
            Console.WriteLine("你刚才输入的是{0}", a);
        }
        public static int ReadInt()
        {
            int a;
            bool flag = false;
            do
            {
                try
                {
                    a = int.Parse(Console.ReadLine());
                    flag = true;
                    return a;
                }
                catch
                {
                    Console.WriteLine("输入有误！请重新输入。");
                    flag = false;
                }
            } while (flag==false);
请问哪里有错误！！！

catch里是不正确的值，程序最终还会在try里面返回一个a，请问这为什么错？

ok，谢谢帮忙！！！