Envió de notificaciones Push en Xamarin

Table of Contents
1 1
2 9
3 26

1 Android
1. Configure un nuevo proyecto en https://console.firebase.google.com/. Es importante pasar a la pestaña de
“Mensajería en la nube” y copiar la clave del servidor y el ID del remitente (los vamos a necesitar más adelante):
Servidor: AAAA788R8VI:APA91bEgD8wN-
Dha9A0rSkJq7E7d3ecRL1iuAza44TVsen9BLuFRDI8j7KoRkPGpJIZZlwx1YMu7NX4RqxHWKhPEzcms7t0ZFOY2vzQ2-
L_sRjdW18qylELamNkgq95j6gsPvtkdCLHw
Remitente: 1029971243346

2. Configurar el Notification Hub en Azure. Click en New, luego: Web + Mobile, luego en: Notification Hub. Colocar
un nombre al Hub y al Namespace. Debe quedar algo como esto:
Luego entrar al Hub y configurar la clave obtenida de Google en el primer paso:

No cierres esto, porque vamos a necesitar copiar una cadena de conexión más luego

3. Crear la aplicación que se suscriba el Hub de notificaciones. Crea la aplicación Xamarin Forms, y asegúrate que
esté funcionando el “Welcome to xamarin forms!”.

Nota 1: para estas pruebas vamos a necesitar un teléfono fijo, no sirve para emuladores.
Nota 2: el proyecto debe tener un paquete, y el nombre de este debe empezar por una letra minúscula, esto es MUY
importante. Por ejemplo:

4. En el proyecto Android, adicione los nuggets de Xamarin.Azure.Notifications.Android y

Xamarin.GooglePlayservices.Gcm:
 Adicional a esto, agregue la GCM.Client.dll que la puedes buscar en internet o sacar de mi repositorio:

5. En el proyecto Android, crea la clase Constants con el siguiente código:

namespace Sales.Droid
{
public static class Constants
{
public const string SenderID = "306406327100";
public const string ListenConnectionString =
"Endpoint=sb://saleszuluhub.servicebus.windows.net/;SharedAccessKeyName=DefaultFullSharedAccessSignature;SharedAccessKey
=R5/o5U0IuwNjYISkktWxK7mY8R4i9xQMtGtMlma1VOk=";
public const string NotificationHubName = "Sales";
}
}

Reemplace el SenderID por el obtenido en el Firebase y el nombre del Hub:

Reemplace el ListenConnectionString por la configuración del Azure, del Hub en Access Polices:
Reemplace el NotificationHubName por el que se asignó en la configuración de Azure.

6. Modifique el MainActivity.cs:
using Android.App;
using Android.Content.PM;
using Android.OS;

namespace Soccer.Droid
{
[Activity(Label = "Soccer", Icon = "@drawable/ic_launcher", Theme = "@style/MainTheme",
MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
#region Singleton
private static MainActivity instance;

public static MainActivity GetInstance()

{
if (instance == null)
{
instance = new MainActivity();
}

return instance;
}
#endregion

#region Methods
protected override void OnCreate(Bundle bundle)
{
instance = this;

TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;

base.OnCreate(bundle);

global::Xamarin.Forms.Forms.Init(this, bundle);
LoadApplication(new App());
 }
#endregion
}
}

7. En el proyecto compartido en el folder de Interfaces, crea la interfaz IRegisterDevice:

public interface IRegisterDevice
{
void RegisterDevice();
}

8. En el proyecto Android Adiciona la clase RegistrationDevice:

[assembly: Xamarin.Forms.Dependency(typeof(Sales.Droid.Implementations.RegistrationDevice))]

namespace Sales.Droid.Implementations
{
using Interfaces;
using Gcm.Client;
using Android.Util;

public class RegistrationDevice : IRegisterDevice

{
#region Methods
public void RegisterDevice()
{
var mainActivity = MainActivity.GetInstance();
GcmClient.CheckDevice(mainActivity);
GcmClient.CheckManifest(mainActivity);

Log.Info("MainActivity", "Registering...");
GcmClient.Register(mainActivity, Droid.Constants.SenderID);
}
#endregion
}
}

9. Crea la nueva clase: MyBroadcastReceiver con este código:

[assembly: Android.App.Permission(Name = "@PACKAGE_NAME@.permission.C2D_MESSAGE")]
[assembly: Android.App.UsesPermission(Name = "@PACKAGE_NAME@.permission.C2D_MESSAGE")]
[assembly: Android.App.UsesPermission(Name = "com.google.android.c2dm.permission.RECEIVE")]
[assembly: Android.App.UsesPermission(Name = "android.permission.GET_ACCOUNTS")]
[assembly: Android.App.UsesPermission(Name = "android.permission.INTERNET")]
[assembly: Android.App.UsesPermission(Name = "android.permission.WAKE_LOCK")]

namespace Sales.Droid
{
using System;
using System.Collections.Generic;
using System.Text;
using Android.App;
using Android.Content;
using Android.Util;
using Gcm.Client;
using ViewModels;
using WindowsAzure.Messaging;

[BroadcastReceiver(Permission = Gcm.Client.Constants.PERMISSION_GCM_INTENTS)]
[IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_MESSAGE }, Categories = new string[] {
"@PACKAGE_NAME@" })]
 [IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_REGISTRATION_CALLBACK }, Categories = new
string[] { "@PACKAGE_NAME@" })]
[IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_LIBRARY_RETRY }, Categories = new string[] {
"@PACKAGE_NAME@" })]

public class MyBroadcastReceiver : GcmBroadcastReceiverBase<PushHandlerService>

{
public static string[] SENDER_IDS = new string[] { Constants.SenderID };

public const string TAG = "MyBroadcastReceiver-GCM";

}

[Service]
public class PushHandlerService : GcmServiceBase
{
#region Properties
public NotificationHub Hub { get; set; }
public static string RegistrationID { get; private set; }
#endregion

#region Methods
public PushHandlerService() : base(Constants.SenderID)
{
Log.Info(MyBroadcastReceiver.TAG, "PushHandlerService() constructor");
}

protected override void OnMessage(Context context, Intent intent)

{
Log.Info(MyBroadcastReceiver.TAG, "GCM Message Received!");

var msg = new StringBuilder();

if (intent != null && intent.Extras != null)

{
foreach (var key in intent.Extras.KeySet())
msg.AppendLine(key + "=" + intent.Extras.Get(key).ToString());
}

var message = intent.Extras.GetString("Message");

var type = intent.Extras.GetString("Type");

if (!string.IsNullOrEmpty(message))
{
var notification = intent.Extras.GetString("Notification");
createNotification("Sales App", message);
}
}

protected override bool OnRecoverableError(Context context, string errorId)

{
Log.Warn(MyBroadcastReceiver.TAG, "Recoverable Error: " + errorId);

return base.OnRecoverableError(context, errorId);

}

protected override void OnError(Context context, string errorId)

{
Log.Error(MyBroadcastReceiver.TAG, "GCM Error: " + errorId);
}

protected override void OnRegistered(Context context, string registrationId)

{
 Log.Verbose(MyBroadcastReceiver.TAG, "GCM Registered: " + registrationId);
RegistrationID = registrationId;

Hub = new NotificationHub(Constants.NotificationHubName, Constants.ListenConnectionString, context);

try
{
Hub.UnregisterAll(registrationId);
}
catch (Exception ex)
{
Log.Error(MyBroadcastReceiver.TAG, ex.Message);
}

var tags = new List<string>() { };

var mainviewModel = MainViewModel.GetInstance();

if (mainviewModel.UserASP != null)
{
var userId = mainviewModel.UserASP.Id;
tags.Add("userId:" + userId);
}

try
{
var hubRegistration = Hub.Register(registrationId, tags.ToArray());
}
catch (Exception ex)
{
Log.Error(MyBroadcastReceiver.TAG, ex.Message);
}
}

protected override void OnUnRegistered(Context context, string registrationId)

{
Log.Verbose(MyBroadcastReceiver.TAG, "GCM Unregistered: " + registrationId);

createNotification("Sales App", "The device has been unregistered!");

}

void createNotification(string title, string desc)

{
//Create notification
var notificationManager = GetSystemService(Context.NotificationService) as NotificationManager;

//Create an intent to show UI

var uiIntent = new Intent(this, typeof(MainActivity));

//Create the notification

var notification = new Notification(Android.Resource.Drawable.SymActionEmail, title);

//Auto-cancel will remove the notification once the user touches it

notification.Flags = NotificationFlags.AutoCancel;

//Set the notification info

//we use the pending intent, passing our ui intent over, which will get called
//when the notification is tapped.
notification.SetLatestEventInfo(this, title, desc, PendingIntent.GetActivity(this, 0, uiIntent, 0));

//Show the notification

notificationManager.Notify(1, notification);
dialogNotify(title, desc);
 }

protected void dialogNotify(String title, String message)

{
var mainActivity = MainActivity.GetInstance();
mainActivity.RunOnUiThread(() =>
{
AlertDialog.Builder dlg = new AlertDialog.Builder(mainActivity);
AlertDialog alert = dlg.Create();
alert.SetTitle(title);
alert.SetButton("Accept", delegate
{
alert.Dismiss();
});
alert.SetIcon(Resource.Drawable.ic_launcher);
alert.SetMessage(message);
alert.Show();
});
}
#endregion
}
}

10. En la MainViewModel crea el método RegisterDevice:

public void RegisterDevice()
{
var register = DependencyService.Get<IRegisterDevice>();
register.RegisterDevice();
}

11. En la LoginViewModel llamar el método de registro, justo después que el usuario ingrese al sistema:
var userASP = (MyUserASP)response.Result;
MainViewModel.GetInstance().UserASP = userASP;
MainViewModel.GetInstance().RegisterDevice();
Settings.UserASP = JsonConvert.SerializeObject(userASP);

En el login por redes sociales y usuario recordado, también.

Por el momento con esto queda listo en Android, ahora vamos a configurar en iOS.

2 iOS
12. Click Keychain Access, expand Certificate Assistant, then click Request a Certificate from a Certificate
Authority....
Select your User Email Address and Common Name , make sure that Saved to disk is selected, and then click Continue.
Leave the CA Email Address field blank as it is not required.

Type a name for the Certificate Signing Request (CSR) file in Save As, select the location in Where, then click Save.
This saves the CSR file in the selected location; the default location is in the Desktop. Remember the location chosen for
this file.

Next, you will register your app with Apple, enable push notifications, and upload this exported CSR to create a push
certificate.

13. If you have not already registered your app, navigate to the iOS Provisioning Portal at the Apple Developer
Center, log on with your Apple ID, click Identifiers, then click App IDs, and finally click on the + sign to register a
new app.

Update the following three fields for your new app and then click Continue:
● Name: Type a descriptive name for your app in the Name field in the App ID Description section.
● Bundle Identifier: Under the Explicit App ID section, enter a Bundle Identifier in the form <Organization
Identifier>.<Product Name>as mentioned in the App Distribution Guide. The Organization
 Identifierand Product Name you use must match the organization identifier and product name you will
use when you create your XCode project. In the screeshot below NotificationHubs is used as a
organization idenitifier and GetStarted is used as the product name. Making sure this matches the
values you will use in your XCode project will allow you to use the correct publishing profile with XCode.
● Push Notifications: Check the Push Notifications option in the App Services section, .
This generates your App ID and requests you to confirm the information. Click Register to confirm the new App ID. Once
you click Register, you will see the Registration complete screen, as shown below. Click Done.

In the Developer Center, under App IDs, locate the app ID that you just created, and click on its row.
Clicking on the app ID will display the app details. Click the Edit button at the bottom.
Scroll to the bottom of the screen, and click the Create Certificate... button under the section Development Push SSL
Certificate.
This displays the "Add iOS Certificate" assistant.

14. Click Choose File, browse to the location where you saved the CSR file that you created in the first task, then
click Generate.

15. After the certificate is created by the portal, click the Download button, and click Done.

This downloads the certificate and saves it to your computer in your Downloads folder.
Double-click the downloaded push certificate aps_development.cer.
This installs the new certificate in the Keychain, as shown below:

16. In
Keychain Access,
right-click the
new push
certificate that
you created in
the Certificates ca
tegory.
Click Export,
name the file,
select
the .p12 format,
and then
click Save.
 Make a note of the file name and location of the exported .p12 certificate. It will be used to enable
authentication with APNS.

17. Back in the iOS Provisioning Portal, select Provisioning Profiles, select All, and then click the + button to create a
new profile. This launches the Add iOS Provisiong Profile Wizard

18. Select iOS App Development under Development as the provisiong profile type, and click Continue.

19. Next, select the app ID you just created from the App ID drop-down list, and click Continue
20. In the Select certificates screen, select your usual development certificate used for code signing, and
click Continue. This is not the push certificate you just created.
21. Next, select the Devices to use for testing, and click Continue

22. Finally, pick a name for the profile in Profile Name, click Generate.
 23. When the new provisioning profile is created click to download it and install it on your Xcode development
machine. Then click Done.

24. As we want to configure the APNS connection, in the Azure Portal, open your Notification Hub settings, ande
click on Notification Services, and then click the Apple (APNS) item in the list. Once done, click on Upload
Certificate and select the .p12 certificate that you exported earlier, as well as the password for the certificate.

Make sure to select Sandbox mode since you will be sending push messages in a development environment. Only use
the Production setting if you want to send push notifications to users who already purchased your app from the
store.
Your notification hub is now configured to work with APNS, and you have the connection strings to register your app and
send push notifications.

25. Crear la clase Constans.cs:

public class Constants
{
// Azure app-specific connection string and hub path
public const string ConnectionString = "Endpoint=sb://tataapphub.servicebus.windows.net/;" +
"SharedAccessKeyName=DefaultFullSharedAccessSignature;" +
"SharedAccessKey=YU3JHje7mazlgYqlCvre8KbWIvL9vehKyYgM2JKya8U=";
public const string NotificationHubPath = "TataApp";
}

26. Haga los siguientes cambios en el AppDelegate.cs:

namespace Sales.iOS
{
using System;
using System.Collections.Generic;
using Foundation;
using ImageCircle.Forms.Plugin.iOS;
using ViewModels;
using UIKit;
using WindowsAzure.Messaging;

[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public SBNotificationHub Hub { get; set; }

public override bool FinishedLaunching(UIApplication app, NSDictionary options)

{
global::Xamarin.Forms.Forms.Init();
ImageCircleRenderer.Init();
Xamarin.FormsMaps.Init();
LoadApplication(new App());

if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
var pushSettings = UIUserNotificationSettings.GetSettingsForTypes(
UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound,
new NSSet());

UIApplication.SharedApplication.RegisterUserNotificationSettings(pushSettings);
UIApplication.SharedApplication.RegisterForRemoteNotifications();
}
else
{
UIRemoteNotificationType notificationTypes = UIRemoteNotificationType.Alert | UIRemoteNotificationType.Badge | UIRemoteNotificationType.Sound;
UIApplication.SharedApplication.RegisterForRemoteNotificationTypes(notificationTypes);
}

return base.FinishedLaunching(app, options);

}

public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)

{
Hub = new SBNotificationHub(Constants.ConnectionString, Constants.NotificationHubPath);

Hub.UnregisterAllAsync(deviceToken, (error) =>

{
if (error != null)
{
Console.WriteLine("Error calling Unregister: {0}", error.ToString());
return;
}

var tags_list = new List<string>() { };

var mainviewModel = MainViewModel.GetInstance();
if (mainviewModel.UserASP != null)
{
var userId = mainviewModel.UserASP.Id;
tags_list.Add("userId:" + userId);
}

var tags = new NSSet(tags_list.ToArray());

Hub.RegisterNativeAsync(deviceToken, tags, (errorCallback) =>
{
if (errorCallback != null)
Console.WriteLine("RegisterNativeAsync error: " + errorCallback.ToString());
});
});
}

public override void ReceivedRemoteNotification(UIApplication application, NSDictionary userInfo)

{
ProcessNotification(userInfo, false);
}

void ProcessNotification(NSDictionary options, bool fromFinishedLaunching)

{
if (null != options && options.ContainsKey(new NSString("aps")))
{
NSDictionary aps = options.ObjectForKey(new NSString("aps")) as NSDictionary;

string alert = string.Empty;

string type = string.Empty;
string notification = string.Empty;
 if (aps.ContainsKey(new NSString("alert")))
{
alert = (aps[new NSString("alert")] as NSString).ToString();
}

//type = (aps[new NSString("Type")] as NSString).ToString();

if (!fromFinishedLaunching)
{
//notification = (aps[new NSString("Notification")] as NSString).ToString();
var avAlert = new UIAlertView("Sales App", alert, null, "Ok", null);
avAlert.Show();
}
}
}

public override void FailedToRegisterForRemoteNotifications(UIApplication application, NSError error)

{
new UIAlertView("Error registering push notifications", error.LocalizedDescription, null, "OK", null).Show();
}
}
}

27. Adicione este clase en el proyecto iOS:

[assembly: Xamarin.Forms.Dependency(typeof(Sales.iOS.Implementations.RegistrationDevice))]

namespace Sales.iOS.Implementations
{
using Foundation;
using Interfaces;
using UIKit;

public class RegistrationDevice : IRegisterDevice

{
#region Methods
public void RegisterDevice()
{
if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
var pushSettings = UIUserNotificationSettings.GetSettingsForTypes(
UIUserNotificationType.Alert |
UIUserNotificationType.Badge |
UIUserNotificationType.Sound,
new NSSet());

UIApplication.SharedApplication.RegisterUserNotificationSettings(pushSettings);
UIApplication.SharedApplication.RegisterForRemoteNotifications();
}
else
{
UIRemoteNotificationType notificationTypes =
UIRemoteNotificationType.Alert |
UIRemoteNotificationType.Badge |
UIRemoteNotificationType.Sound;
UIApplication.SharedApplication.RegisterForRemoteNotificationTypes(notificationTypes);
}
}
#endregion
}
}

3 Test
28. Corra las aplicaciones (Android & iOS) en un dispositivo (no en emulador) e ingrese al Hub en el portal de Azure
y envíe una notificación de prueba:
Verifique que el mensaje llegue con la aplicación corriendo, la aplicación minimizada y la aplicación cerrada.

29. Por último, creemos una aplicación de consola que envíe mensajes al Hub. Agregue este paquete a la aplicación
de consola:

Install-Package Microsoft.Azure.NotificationHubs

30. Cambie el código de la clase Program por el siguiente:

using Microsoft.Azure.NotificationHubs;
using System;

namespace NotificationsSender
{
public class Program
{
private static NotificationHubClient hub;

public static void Main(string[] args)

{
hub =
NotificationHubClient.CreateClientFromConnectionString("Endpoint=sb://zuluhub.servicebus.windows.net/;S
haredAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=SmhFDkgkbg5z5dKu2OTU7ds1iHw1i3BM5ifsHJ2rij
k=", "Zulu");

do
{
Console.WriteLine("Type a new message:");
var message = Console.ReadLine();
SendNotificationAsync(message);
Console.WriteLine("The message was sent...");
} while (true);
}

private static async void SendNotificationAsync(string message)

{
await hub.SendGcmNativeNotificationAsync("{ \"data\" : {\"message\":\"" + message +
"\"}}");
}
 }
}

31. ¡Prueba tu aplicación!

Este documento es una adaptación del sitio: https://docs.microsoft.com/en-us/azure/notification-hubs/xamarin-

notification-hubs-push-notifications-android-gcm