问asp.net，使用服务器证书生成httpwebrequest C#

EN

   protected void Page_Load(object sender, EventArgs e)
   { 
        ServicePointManager.ServerCertificateValidationCallback += new System.Net.Security.RemoteCertificateValidationCallback(ValidateServerCertificate);

        ServicePointManager.MaxServicePointIdleTime = 300000;

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://url");
        request.Accept = "text/xml, */*";
        request.Method = "GET";
        request.Headers.Add(HttpRequestHeader.AcceptLanguage, "en-us");
        request.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; .NET CLR 3.5.30729;)";
        request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
        request.Credentials = CredentialCache.DefaultCredentials;
        request.KeepAlive = false;

        X509Certificate myCert = null;
        X509Store store = new X509Store("My");

        store.Open(OpenFlags.ReadOnly);

        int i = 0;
        foreach (X509Certificate2 m in store.Certificates)
        {
             if (i == 0)
                myCert = m;
             i++;
        }

        if (myCert != null)
        {
             request.ClientCertificates.Add(myCert);
        }

        //take the response and create the xml document to parse
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader reader = new StreamReader(response.GetResponseStream());
        string str = reader.ReadToEnd();

        ...
        }

        public static bool ValidateServerCertificate(object sender, X509Certificate certificate,X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            //certificate is in here
            if (sslPolicyErrors == SslPolicyErrors.None)
               return true;

            sslPE = "SSLPolicyErros: " + sslPolicyErrors;

            return false;
        }