Sending Push Notifications to Android with C#

Introduction

This tutorial shows you how to use C# to send push notifications to an Android application. You'll create a Android app with some customization that receives push notifications by using Firebase Cloud Messaging (FCM).

What is Push Notification

Push notifications let your application notify a user of new messages or events even when the user is not actively using your application.

How It Works

Prerequisites

Below are some prerequisites required:

1. Latest version of Android Studio
2. Account in FCM

Completing this tutorial is a prerequisite for all other Notification Hubs tutorials for Android apps.

Creating a Project FCM

1. Navigate to the Firebase Console, sign in with your Google account crendentials.
2. Click Add project.

   

3. Type in your new Project name and click Create project.

   

4. Select newly created project, click on gear at top left and select project settings.

   

5. In the project settings, go to cloud messaging tab and make note of the server key.

   

Create and Connect Your App to the Notification Hub

Create a New Android Project

1. In Android Studio, start a new Android Studio project.

   

2. Choose the Phone and Tablet form factor and the Minimum SDK that you want to support. Then click Next.

   

3. Choose Empty Activity for the main activity, click Next, and then click Finish.

Connect App to the Notification Hub

1. Click Tools -> Firebase on the menu. It will open Firebase Assistant as shown below. Open Set up Firebase Cloud Messaging.

   

2. Connect your app to firebase by providing firebase credential and then select your project which was earlier created on Firebase in this demo.
3. Ideally this is enough to get push notification……further we can discuss how to send customize notification and use it.

   

Customizing Android App

1. In the Project View, expand app > src > main > java. Right-click your package folder under Java, click New, and then click Java Class. Add a new class named FirebaseMessagingService.

   

2. Copy and paste the below code:
   Java

   package notification.com.test.testnewnotification;
   
   import android.app.NotificationManager;
   import android.app.PendingIntent;
   import android.content.Context;
   import android.content.Intent;
   import android.graphics.BitmapFactory;
   import android.media.RingtoneManager;
   import android.net.Uri;
   import android.support.v4.app.NotificationCompat;
   import android.util.Log;
   
   import com.google.firebase.messaging.RemoteMessage;
   
   /**
    * Created by Ashish.kapoor on 04.09.2017.
    */
   
   public class FirebaseMessagingService 
   extends  com.google.firebase.messaging.FirebaseMessagingService {
       private static final String TAG="FirebaseMessagingServic";
   
       public FirebaseMessagingService() {
       }
   
       @Override
       public void onMessageReceived(RemoteMessage remoteMessage) {
   
           String strTitle=remoteMessage.getNotification().getTitle();
           String message=remoteMessage.getNotification().getBody();
           Log.d(TAG,"onMessageReceived: 
           Message Received: \n" +
           "Title: " + strTitle + "\n" +
           "Message: "+ message);
   
           sendNotification(strTitle,message);
       }
   
       @Override
       public void onDeletedMessages() {
   
       }
   
       private  void sendNotification(String title,String messageBody) {
           Intent[] intents= new Intent[1];
             Intent intent= new      Intent(this,MainActivity.class);
           intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
           intent.putExtra("IncidentNo", title);
           intent.putExtra("ShortDesc", messageBody);
           intent.putExtra("Description",messageBody);
           intents[0]=intent;
           PendingIntent pendingIntent=PendingIntent.getActivities(this,0,
           intents,PendingIntent.FLAG_ONE_SHOT);
           Uri defaultSoundUri= RingtoneManager.getDefaultUri
           (RingtoneManager.TYPE_NOTIFICATION);
           NotificationCompat.Builder notificationbuilder= 
           new NotificationCompat.Builder(this)
                   .setSmallIcon(R.drawable.ic_stat_name)
                   .setContentTitle("Service Now")
                   .setContentText(messageBody)
                   .setAutoCancel(true)
                   .setSound(defaultSoundUri)
                   .setContentIntent(pendingIntent)
           .setLargeIcon(BitmapFactory.decodeResource
           (getResources(), R.mipmap.ic_launcher));;
   
           NotificationManager notificationManager=(NotificationManager) 
           getSystemService(Context.NOTIFICATION_SERVICE);
           notificationManager.notify(0, notificationbuilder.build());
       }
   }

3. Open MainActivity class and replace code as below:
   Java

   package notification.com.test.testnewnotification;
   import android.content.Intent;
   import android.net.Uri;
   import android.support.v7.app.AppCompatActivity;
   import android.os.Bundle;
   import android.view.View;
   import android.widget.TextView;
   import com.google.firebase.messaging.FirebaseMessaging;
   public class MainActivity extends AppCompatActivity {
     static   String strSDesc = "ShortDesc";
      static String strIncidentNo = "IncidentNo";
      static String strDesc="IncidentNo";
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           onNewIntent(getIntent());
          FirebaseMessaging.getInstance().
          subscribeToTopic("ServiceNow");
       }
   
       @Override
       public void onNewIntent(Intent intent) {
           Bundle extras = intent.getExtras();
           if (extras != null) {
               setContentView(R.layout.activity_main);
               final TextView IncidentTextView = 
               (TextView) findViewById(R.id.txtIncidentNo);
               final TextView SDescTextView = 
               (TextView) findViewById(R.id.txtShortDesc);
   
               final TextView DescTextView = 
               (TextView) findViewById(R.id.txtDesc);
                strSDesc = extras.getString("ShortDesc",
                "ShortDesc");
                strIncidentNo = extras.getString("IncidentNo",
                "IncidentNo");
                strDesc=extras.getString("Description",
                "IncidentNo");
   
               IncidentTextView.setText(strIncidentNo);
                       SDescTextView.setText(strSDesc);
               DescTextView.setText(strDesc);
           }
       }
   
       public void browser1(View view){
           Intent browserIntent =new Intent
           (Intent.ACTION_VIEW, Uri.parse
           ("https://somebrowser?uri=incident.do?sysparm_query=number="
           +strIncidentNo));
           startActivity(browserIntent);
       }
   }

4. Open Activity_main.xml and add 3 textView and one command button as below:

   

   Type	ID	Default Text
   TextView	txtIncidentNo	Incident No
   TextView	txtShortDesc	Short Description
   TextView	txtDesc	Description
   Button	btnGetData	Get Data OnClick browser1

5. Build your app and run it.

(Optional) Sending Push Notifications from Firebase Portal

Normally, you would send notifications using a backend server. This is just to test your Notification App.

1. Open FCM console, select your project and then open Notifications from left toolbar.

   

2. Enter Message text, set Target as user segment and select your app. Click on advance option update Title and add Custom data as below and click on send message.

   

   

3. Wow, you received notification message on your mobile, please find the below screenshots for the same.

   

Creating C# App

Nothing big!

Create your C# application and use the below code:

     public static String SendNotificationFromFirebaseCloud()
        {
            var result = "-1";
            var webAddr = "https://fcm.googleapis.com/fcm/send";
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(webAddr);
            httpWebRequest.ContentType = "application/json";
            httpWebRequest.Headers.Add(HttpRequestHeader.Authorization,"key=your FCM senderkey");
            httpWebRequest.Method = "POST";
            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                string strNJson = @"{
                    ""to"": ""/topics/ServiceNow"",
                    ""data"": {
                        ""ShortDesc"": ""Some short desc"",
                        ""IncidentNo"": ""any number"",
                        ""Description"": ""detail desc""
  },
  ""notification"": {
                ""title"": ""ServiceNow: Incident No. number"",
    ""text"": ""This is Notification"",
""sound"":""default""
  }
        }";
                streamWriter.Write(strNJson);
                streamWriter.Flush();
            }

            var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                result = streamReader.ReadToEnd();
            }
            return result;
        }