c#推送通知中的System.Security.SecurityException

我有一个Asp.net web服务应用程序，我正在向android设备发送推送通知。当我在本地运行我的web服务时，它工作得很好，但当我尝试在web主机中运行web服务时，我得到了以下错误。知道吗?

System.Web.Services.Protocols。SoapException:服务器无法处理请求。--> System.Security.SecurityException:请求类型为System.Security.Permissions的权限。SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.日志含义在System.Security.CodeAccessSecurityEngine。检查对象需求，StackCrawlMark&stackMark, Boolean isPermSet在System.Security.CodeAccessPermission.Demand ()在System.Net.ServicePointManager。set_ServerCertificateValidationCallback (RemoteCertificateValidationCallback价值)在BitirmeServis.AndroidGCMPushNotification。SendGCMNotification(String deviceID, String message, Int32 pushCode, String apiKey, String contentTitle, String err) in c:'users'fatih polat'documents'visual studio 2010'Projects'BitirmeServis'BitirmeServis'AndroidGCMPushNotification.cs:line 31在BitirmeServis.Service1。call_taxi(字符串taxid，字符串userId，字符串userLatitude，字符串userLongitude，字符串targetlat，字符串targetlon，字符串onerilenfiyat) in c:'users'fatih polat'documents'visual studio 2010'Projects'BitirmeServis'BitirmeServis'Service1.asmx.cs:line 97失败的行动是:需求第一个失败的权限类型是:System.Security.Permissions.SecurityPermission第一个失败的权限是:

这是我的c#类

 public static string SendGCMNotification(string deviceID, string message, int pushCode, string apiKey, string contentTitle, string err)
    {
        //string apiKey = Constants.GCM_BROWSER_API_KEY;
        string postDataContentType = "application/json";
        // contentTitle= Constants.PUSH_CODE_STRS[pushCode]
        string postData =
        "{ '"registration_ids'": [ '"" + deviceID + "'" ], " +
          "'"data'": {'"pushCode'":'"" + pushCode.ToString() + "'", " +
                     "'"contentTitle'":'"" + contentTitle + "'", " +
                     "'"message'": '"" + message + "'"}}";
        ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateServerCertificate);
        //  MESSAGE CONTENT
        byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        //
        //  CREATE REQUEST
        HttpWebRequest Request = null;
        try
        {
            Request = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
        }
        catch (Exception ex)
        {
            err = ex.ToString();
            return "error";
        }
        if (Request == null)
        {
            err = "Boş Request";
            return "error";
        }
        Request.Method = "POST";
        Request.KeepAlive = false;
        Request.ContentType = postDataContentType;
        Request.Headers.Add(string.Format("Authorization: key={0}", apiKey));
        Request.ContentLength = byteArray.Length;
        Stream dataStream = null;
        try
        {
            dataStream = Request.GetRequestStream();
            dataStream.Write(byteArray, 0, byteArray.Length);
            dataStream.Close();
        }
        catch (Exception ex)
        {
            err = ex.ToString();
            return "error";
        }

        try
        {
            WebResponse Response = Request.GetResponse();
            HttpStatusCode ResponseCode = ((HttpWebResponse)Response).StatusCode;
            if (ResponseCode.Equals(HttpStatusCode.Unauthorized) || ResponseCode.Equals(HttpStatusCode.Forbidden))
            {
                var text = "Unauthorized - need new token";
            }
            else if (!ResponseCode.Equals(HttpStatusCode.OK))
            {
                var text = "Response from web service isn't OK";
            }
            StreamReader Reader = new StreamReader(Response.GetResponseStream());
            string responseLine = Reader.ReadToEnd();
            Reader.Close();
            return responseLine;
        }
        catch (Exception ex)
        {
            err = ex.ToString();
            return "error";
        }
    }

    public static bool ValidateServerCertificate(
                                                object sender,
                                                X509Certificate certificate,
                                                X509Chain chain,
                                                SslPolicyErrors sslPolicyErrors)
    {
        return true;
    }
}

ServicePointManager.ServerCertificateValidationCallback +=
    new RemoteCertificateValidationCallback(ValidateServerCertificate);