error System.Net.WebException: The remote server returned an error: (401) Unauthorized. - gcm

See more:

ASP

hi
I posted notifications from project(asp mvc) with gcm.

I receive the following error when sending notifications.

and am checked the api key and sender id both are same.

error System.Net.WebException: The remote server returned an error: (401) Unauthorized.

please guide me.

public Notification PushToAndroidDevice(string registrationid, string message)
{
Notification notification = new Notification();
//try
//{
//var applicationID = "Axxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxs";//Server Key
var applicationID = "Axxxxxxxxxxxxxxxxxxxxxxxxxxxxs";//Browser Key
var SENDER_ID = "2xxxxxxxxxxxxxxxxxxxx5";

WebRequest tRequest;
tRequest = WebRequest.Create("https://android.googleapis.com/gcm/send");
tRequest.Method = "post";

tRequest.ContentType = "application/x-www-form-urlencoded";
//tRequest.Headers.Add(string.Format("Authorization: key={0}", applicationID));
tRequest.Headers.Add(HttpRequestHeader.Authorization, "key=AIxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxs");

tRequest.Headers.Add(string.Format("Sender: id={0}", SENDER_ID));

string postData = "collapse_key=score_update&time_to_live=108&delay_while_idle=1&data.message=" + message + "&data.time=" + System.DateTime.Now.ToString() + "®istration_id=" + registrationid + "";

Byte[] byteArray = Encoding.UTF8.GetBytes(postData);
tRequest.ContentLength = byteArray.Length;

Stream dataStream = tRequest.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();

WebResponse tResponse = tRequest.GetResponse();

dataStream = tResponse.GetResponseStream();

StreamReader tReader = new StreamReader(dataStream);

String sResponseFromServer = tReader.ReadToEnd();

notification.Message = sResponseFromServer;
tReader.Close();
dataStream.Close();
tResponse.Close();

notification.Status = true;
//}
//catch (Exception ex)
//{
// notification.Status = false;
// notification.Message = "ERROR DESCRIPTION : " + ex.Message;
//}
return notification;
}