How to Setup Firebase Push Notifications with a .NET Backend

These parameters are:

• deviceTokens: An array of strings, each string represents a FCM token provided by Firebase on each app-installation. This is going to be the list of app-installations that the notification is going to send.
• title: It’s the bold section of a notification.
• body: It represents ‘Message text’ field of the Firebase SDK, this is the message you want to send to the users.
• data: These is a dynamic object, it can be whatever you want because this object is going to be used as additional information you want to send to the app, it’s like hidden information. For example an action you want to execute when the user presses on the notification or an id of some product.

For the method, I am going to suppose that all parameters are correct without bad values (you can add all the validations you want). The first thing we have to do is to create an object with all the data we need to send to the API, I created two classes for that:

public class Message  
{
  public string[] registration_ids { get; set; }
  public Notification notification { get; set; }
  public object data { get; set; }
}
public class Notification  
{
  public string title { get; set; }
  public string text { get; set; }
}

Then, just create a new object of type ‘Message’ and serialize it as I did it here:

var messageInformation = new Message()  
{
  notification = new Notification()
  {
    title = title,
    text = body
  },
  data = data,
  registration_ids = deviceTokens
};
//Object to JSON STRUCTURE => using Newtonsoft.Json;
string jsonMessage = JsonConvert.SerializeObject(messageInformation);  

Now we just need a request to Firebase API and we’re done.

The request has to be as a “Post” Method to the Firebase API-Url, we have to add a Header which is “Authorization” and use a value like: “key={YourServerKey}”.

Then we add the content (jsonMessage) and you are ready to hit the api.

Here it is the code you need to do the last part:

// Create request to Firebase API
var request = new HttpRequestMessage(HttpMethod.Post, FireBasePushNotificationsURL);  
request.Headers.TryAddWithoutValidation(“Authorization”, “key=” + ServerKey);  
request.Content = new StringContent(jsonMessage, Encoding.UTF8, “application/json”);  
HttpResponseMessage result;  
using (var client = new HttpClient())  
{
  result = await client.SendAsync(request);
}