异常处理机制

用实例说话

static void Main(string[] args)
{
    string input;
    while (true)
    {
        try
        {
            Console.WriteLine("请输入0至9之间的整数或按回车退出");
            input = Console.ReadLine();
            if (input == "")
            {
                break;  //按回车退出
            }
            if (Convert.ToByte(input) > 9 || Convert.ToByte(input) < 0)
            {
                throw new IndexOutOfRangeException("你输入的超出范围数字是" + input);
            }
            Console.WriteLine("你刚刚输入的数字是"+input);
        }
        catch (IndexOutOfRangeException ex1)  //捕获特定的异常
        {
            Console.WriteLine("IndexOutOfRangeException错误!" + ex1.Message);
            //ex1.Message对于的信息为("你输入的数字是" + input)
        }
        catch(Exception ex)  //默认的异常捕获
        {
            Console.WriteLine("未知异常:" + ex.Message);
        }
        finally
        {
            Console.WriteLine("此判断已完成，请再次输入");
        }

    }
}