问在firebase cloud messaging create messaging页面中显示了发送所有完整选项的方法

EN

    private static string SendPushNotification()
{
            string response;

            try
            {
            string serverKey = "##########"; 
            string senderId = "#############";
            string deviceId = "//topics/all";

            WebRequest tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");

            tRequest.Method = "post";
            tRequest.ContentType = "application/json";
            var data = new
            {
                to = deviceId,
                notification = new
                {
                    body = "Greetings",
                    title = "Augsburg",
                    sound = "Enabled"
                }
            };

            var serializer = new JavaScriptSerializer();
            var json = serializer.Serialize(data);
            Byte[] byteArray = Encoding.UTF8.GetBytes(json);
            tRequest.Headers.Add(string.Format("Authorization: key={0}", serverKey));
            tRequest.Headers.Add(string.Format("Sender: id={0}", senderId));
            tRequest.ContentLength = byteArray.Length;

            using (Stream dataStream = tRequest.GetRequestStream())
            {
                dataStream.Write(byteArray, 0, byteArray.Length);
                using (WebResponse tResponse = tRequest.GetResponse())
                {
                    using (Stream dataStreamResponse = tResponse.GetResponseStream())
                    {
                        using (StreamReader tReader = new StreamReader(dataStreamResponse))
                        {
                            String sResponseFromServer = tReader.ReadToEnd();
                            response = sResponseFromServer;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            response = ex.Message;
        }

        return response;
}