使用c#.net检查URL是否工作

当我使用Web请求和Web响应方法检查URL时

bool result = false;
        try
        {
            if (!url.Contains("http://")) url = "http://" + url;
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "HEAD";
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            { if (response.StatusCode == HttpStatusCode.OK) result = true; }
        }
        catch
        {
            return result;
        }
        return result;

但是，当我检查到这个URL"http://payments.rctrustee.org/"我得到错误。所以我得到结果是假的。但我检查到浏览器这个URL是工作的。

i需要这个结果为真;

try
            {
               if (!url.Contains("http://")) url = "http://" + url;
                WebRequest req = WebRequest.Create(url);
                WebResponse res = req.GetResponse();
                Console.WriteLine("Url Exists");
            }
            catch (WebException ex)
            {
                Console.WriteLine(ex.Message);
                if (ex.Message.Contains("remote name could not be resolved"))
                {
                    Console.WriteLine("Url is Invalid");
                }
            }