Shimon Wiener Shimon Wiener - 26 days ago 21
iOS Question

Push Notification in Xamarin Forms

I'm trying to implement Push Notification in PCL app in Xamarin forms IOS. I have a suitable provisioning profile and p12 file that I used to send notification to native app and I'm using it on my Xamarin forms, do I need to do something more beside this changes? I changed the AppDelegate in the IOS project to look like this:

using System;
using System.Collections.Generic;
using System.Linq;

using Foundation;
using UIKit;

namespace Punteam.iOS
{
[Register ("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{

String model = UIDevice.CurrentDevice.Model;
String sysName = UIDevice.CurrentDevice.SystemName;
String sysVer = UIDevice.CurrentDevice.SystemVersion;
NSUserDefaults.StandardUserDefaults.SetString (model, "Model");
NSUserDefaults.StandardUserDefaults.SetString (sysName, "sysName");
NSUserDefaults.StandardUserDefaults.SetString (sysName, "sysVer");

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);
}

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

return base.FinishedLaunching(app, options);
}
//***********************************************************************************************
//** RegisteredForRemoteNotifications *
//***********************************************************************************************

public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
{
// Get current device token
var DeviceToken = deviceToken.Description;
if (!string.IsNullOrWhiteSpace(DeviceToken)) {
DeviceToken = DeviceToken.Trim('<').Trim('>');
}

// Get previous device token
var oldDeviceToken = NSUserDefaults.StandardUserDefaults.StringForKey("PushDeviceToken");

// Has the token changed?
if (string.IsNullOrEmpty(oldDeviceToken) || !oldDeviceToken.Equals(DeviceToken))
{
//TODO: Put your own logic here to notify your server that the device token has changed/been created!
}

// Save new device token
NSUserDefaults.StandardUserDefaults.SetString(DeviceToken, "PushDeviceToken");
}
//***********************************************************************************************
//** ReceivedRemoteNotification *
//***********************************************************************************************

public override void ReceivedRemoteNotification(UIApplication application, NSDictionary userInfo)
{
ProcessNotification(userInfo, false);
}
//***********************************************************************************************
//** ProcessNotification *
//***********************************************************************************************

void ProcessNotification(NSDictionary options, bool fromFinishedLaunching)
{
// Check to see if the dictionary has the aps key. This is the notification payload you would have sent
if (null != options && options.ContainsKey(new NSString("aps")))
{
//Get the aps dictionary
NSDictionary aps = options.ObjectForKey(new NSString("aps")) as NSDictionary;

string alertString = string.Empty;
string paramString = string.Empty;

if (aps.ContainsKey(new NSString("alert")))
alertString = (aps[new NSString("alert")] as NSString).ToString();

if (aps.ContainsKey(new NSString("param")))
paramString = (aps[new NSString("param")] as NSString).ToString();

if (!fromFinishedLaunching)
{
//Manually show an alert
if (!string.IsNullOrEmpty(alertString))
{
UIAlertView avAlert = new UIAlertView("Awesome Notification", alertString , null,
NSBundle.MainBundle.LocalizedString("Cancel", "Cancel"),
NSBundle.MainBundle.LocalizedString("OK", "OK"));

avAlert.Clicked += (sender, buttonArgs) =>
{
if (buttonArgs.ButtonIndex != avAlert.CancelButtonIndex)
{
if (!string.IsNullOrEmpty(paramString))
{
// App.Current.MainPage = new NavigationPage(new PushNotifMessageDisplay(paramString));
}
}
};

avAlert.Show();
}
}
}
}
//***********************************************************************************************
//** FailedToRegisterForRemoteNotifications *
//***********************************************************************************************

public override void FailedToRegisterForRemoteNotifications (UIApplication application , NSError error)
{
new UIAlertView("Error registering push notifications", error.LocalizedDescription, null, "OK", null).Show();
}
}
}

Answer

You can check my full example for push notification here

Regarding the iOS part, this is the relevant code that goes to your AppDelegate:

public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
{
    var deviceTokenString = deviceToken.ToString().Replace("<","").Replace(">", "").Replace(" ", "");
    var notificationService = Resolver.Resolve<IPushNotificationService>();
    var pushNotificationRegister = Resolver.Resolve<IPushNotificationRegister>();

    if (pushNotificationRegister.ShouldSendToken(deviceTokenString))
    {
        var uid = UIDevice.CurrentDevice.IdentifierForVendor.AsString();
        notificationService.AddPushToken(deviceTokenString, DeviceUtils.GetDeviceType(), uid);
    }
}

*IPushNotificationRegister - checks if the token is already sent to the server (it is done to avoid unneeded requests to the server).

*IPushNotificationService - The service to send the token to the server.

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