Send push to Android by C# using FCM (Firebase Cloud Messaging)

Question

I am using this code to send notification message by C# with GCM, using Winforms, Webforms, whatever. Now I want to send to FCM (Firebase Cloud Messaging). Should I update my code? :

public class AndroidGCMPushNotification
{
    public AndroidGCMPushNotification()
    {
        //
        // TODO: Add constructor logic here
        //
    }
    public string SendNotification(string deviceId, string message)
    {
        string SERVER_API_KEY = "server api key";        
        var SENDER_ID = "application number";
        var value = message;
        WebRequest tRequest;
        tRequest = WebRequest.Create("https://android.googleapis.com/gcm/send");
        tRequest.Method = "post";
        tRequest.ContentType = " application/x-www-form-urlencoded;charset=UTF-8";
        tRequest.Headers.Add(string.Format("Authorization: key={0}", SERVER_API_KEY));

        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=" + value + "&data.time=" + System.DateTime.Now.ToString() + "&registration_id=" + deviceId + "";
        Console.WriteLine(postData);
        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();


        tReader.Close();
        dataStream.Close();
        tResponse.Close();
        return sResponseFromServer;
    }
}

but the GCM was changed to FCM. Is this same code to send the notification? Where can I find the SERVER_API_KEY? Is the same solution?

Answer 1

firebase cloud messaging with c#: working all .net platform (asp.net, .netmvc, .netcore)

        WebRequest tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
        tRequest.Method = "post";
        //serverKey - Key from Firebase cloud messaging server  
        tRequest.Headers.Add(string.Format("Authorization: key={0}", "AIXXXXXX...."));
        //Sender Id - From firebase project setting  
        tRequest.Headers.Add(string.Format("Sender: id={0}", "XXXXX.."));
        tRequest.ContentType = "application/json";
        var payload = new
        {
            to = "e8EHtMwqsZY:APA91bFUktufXdsDLdXXXXXX..........XXXXXXXXXXXXXX",
            priority = "high",
            content_available = true,
            notification = new
            {
                body = "Test",
                title = "Test",
                badge = 1
            },
            data = new 
            {
                key1 = "value1",
                key2 = "value2"
            }

        };

        string postbody = JsonConvert.SerializeObject(payload).ToString();
        Byte[] byteArray = Encoding.UTF8.GetBytes(postbody);
        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())
                {
                    if (dataStreamResponse != null) using (StreamReader tReader = new StreamReader(dataStreamResponse))
                        {
                            String sResponseFromServer = tReader.ReadToEnd();
                            //result.Response = sResponseFromServer;
                        }
                }
            }
        }

Answer 2

Here is another approach of writing Notification Service inside ASP.Net REST API.

public async Task<bool> NotifyAsync(string to, string title, string body)
{
    try
    {
        // Get the server key from FCM console
        var serverKey = string.Format("key={0}", "Your server key - use app config");

        // Get the sender id from FCM console
        var senderId = string.Format("id={0}", "Your sender id - use app config");

        var data = new
        {
            to, // Recipient device token
            notification = new { title, body }
        };

        // Using Newtonsoft.Json
        var jsonBody = JsonConvert.SerializeObject(data);

        using (var httpRequest = new HttpRequestMessage(HttpMethod.Post, "https://fcm.googleapis.com/fcm/send"))
        {
            httpRequest.Headers.TryAddWithoutValidation("Authorization", serverKey);
            httpRequest.Headers.TryAddWithoutValidation("Sender", senderId);
            httpRequest.Content = new StringContent(jsonBody, Encoding.UTF8, "application/json");

            using (var httpClient = new HttpClient())
            {
                var result = await httpClient.SendAsync(httpRequest);

                if (result.IsSuccessStatusCode)
                {
                    return true;
                }
                else
                {
                    // Use result.StatusCode to handle failure
                    // Your custom error handler here
                    _logger.LogError($"Error sending notification. Status Code: {result.StatusCode}");
                }
            }
        }
    }
    catch (Exception ex)
    {
        _logger.LogError($"Exception thrown in Notify Service: {ex}");
    }

    return false;
}

References:

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

Answer 3

I have posted this answer as this question was viewed most and this server side code was written in VS 2015 in C# for sending push notification either single device based on device id or subscribed topic to Xamarin Android app

public class FCMPushNotification
{
    public FCMPushNotification()
    {
        // TODO: Add constructor logic here
    }

    public bool Successful
    {
        get;
        set;
    }

    public string Response
    {
        get;
        set;
    }
    public Exception Error
    {
        get;
        set;
    }



    public FCMPushNotification SendNotification(string _title, string _message, string _topic)
    {
        FCMPushNotification result = new FCMPushNotification();
        try
        {
            result.Successful = true;
            result.Error = null;
           // var value = message;
            var requestUri = "https://fcm.googleapis.com/fcm/send";

            WebRequest webRequest = WebRequest.Create(requestUri);
            webRequest.Method = "POST";
            webRequest.Headers.Add(string.Format("Authorization: key={0}", YOUR_FCM_SERVER_API_KEY));
            webRequest.Headers.Add(string.Format("Sender: id={0}", YOUR_FCM_SENDER_ID));
            webRequest.ContentType = "application/json";

            var data = new
            {
               // to = YOUR_FCM_DEVICE_ID, // Uncoment this if you want to test for single device
               to="/topics/"+_topic, // this is for topic 
                notification=new
                {
                    title=_title,
                    body=_message,
                    //icon="myicon"
                }
            };
            var serializer = new JavaScriptSerializer();
            var json = serializer.Serialize(data);

            Byte[] byteArray = Encoding.UTF8.GetBytes(json);

            webRequest.ContentLength = byteArray.Length;
            using (Stream dataStream = webRequest.GetRequestStream())
            {
                dataStream.Write(byteArray, 0, byteArray.Length);

                using (WebResponse webResponse = webRequest.GetResponse())
                {
                    using (Stream dataStreamResponse = webResponse.GetResponseStream())
                    {
                        using (StreamReader tReader = new StreamReader(dataStreamResponse))
                        {
                            String sResponseFromServer = tReader.ReadToEnd();
                            result.Response = sResponseFromServer;
                        }
                    }
                }
            }

        }
        catch(Exception ex)
        {
            result.Successful = false;
            result.Response = null;
            result.Error = ex;
        }
        return result;
    }
}

and its uses

// start sending push notification to apps
                FCMPushNotification fcmPush = new FCMPushNotification();                    
                fcmPush.SendNotification("your notificatin title", "Your body message","news");
                // end push notification

Answer 4

Yes, you should update your code to use Firebase Messaging interface. There's a GitHub Project for that here.

using Stimulsoft.Base.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;

namespace _WEBAPP
{
    public class FireBasePush
    {
        private string FireBase_URL = "https://fcm.googleapis.com/fcm/send";
        private string key_server;
        public FireBasePush(String Key_Server)
        {
            this.key_server = Key_Server;
        }
        public dynamic SendPush(PushMessage message)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(FireBase_URL);
            request.Method = "POST";
            request.Headers.Add("Authorization", "key=" + this.key_server);
            request.ContentType = "application/json";
            string json = JsonConvert.SerializeObject(message);
            //json = json.Replace("content_available", "content-available");
            byte[] byteArray = Encoding.UTF8.GetBytes(json);
            request.ContentLength = byteArray.Length;
            Stream dataStream = request.GetRequestStream();
            dataStream.Write(byteArray, 0, byteArray.Length);
            dataStream.Close();
            HttpWebResponse respuesta = (HttpWebResponse)request.GetResponse();
            if (respuesta.StatusCode == HttpStatusCode.Accepted || respuesta.StatusCode == HttpStatusCode.OK || respuesta.StatusCode == HttpStatusCode.Created)
            {
                StreamReader read = new StreamReader(respuesta.GetResponseStream());
                String result = read.ReadToEnd();
                read.Close();
                respuesta.Close();
                dynamic stuff = JsonConvert.DeserializeObject(result);

                return stuff;
            }
            else
            {
                throw new Exception("Ocurrio un error al obtener la respuesta del servidor: " + respuesta.StatusCode);
            }
        }


    }
    public class PushMessage
    {
        private string _to;
        private PushMessageData _notification;

        private dynamic _data;
        private dynamic _click_action;
        public dynamic data
        {
            get { return _data; }
            set { _data = value; }
        }

        public string to
        {
            get { return _to; }
            set { _to = value; }
        }
        public PushMessageData notification
        {
            get { return _notification; }
            set { _notification = value; }
        }

        public dynamic click_action
        {
            get
            {
                return _click_action;
            }

            set
            {
                _click_action = value;
            }
        }
    }

    public class PushMessageData
    {
        private string _title;
        private string _text;
        private string _sound = "default";
        //private dynamic _content_available;
        private string _click_action;
        public string sound
        {
            get { return _sound; }
            set { _sound = value; }
        }

        public string title
        {
            get { return _title; }
            set { _title = value; }
        }
        public string text
        {
            get { return _text; }
            set { _text = value; }
        }

        public string click_action
        {
            get
            {
                return _click_action;
            }

            set
            {
                _click_action = value;
            }
        }
    }
}