问修改RegEx以匹配主机名和端口号？

EN

@"^(?<hostname>((?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?)*\.?)|localhost)(?::(?<port>\d+))$"

static bool checkHost(string host,int timeout)
{
    if (!host.Contains(':')) 
        return false;
    try
    {
        string[] h = host.Split(':');
        Task e = new TcpClient().ConnectAsync(h[0], int.Parse(h[1]));
        new Task(e.Start);
        Thread.Sleep(timeout);

        return e.IsCompleted;
    }
    catch (SocketException){ }
    catch (ArgumentOutOfRangeException) { }

    return false;
}

bool check = checkHost("google.com:80",1000);