Using Xam.Plugins.Notifier for Local Notifications I am able to show a notification in Android. However, when I tap the notification, it reloads the application. Similar to how a remote notification would.
I handle the OnNewIntent() in the MainActivitiy.cs but it never fires.
How do I tap a Local Notification made by Xam.Plugins.Notifier so that OnNewIntent() fires and I can show a Shell item?
protected async override void OnNewIntent(Intent intent)
{
base.OnNewIntent(intent);
var title = intent.GetStringExtra("title");
if (title != null)
{
await Shell.Current.GoToAsync("Tools/Sales");
}
}
I have a SplashScreen Activity that actually starts the app:
How do I pass the Intent that starts the activity to the MainActitity from the Splash
[Activity(Theme = "#style/MyTheme.Splash", MainLauncher = true, NoHistory = true, LaunchMode = Android.Content.PM.LaunchMode.SingleTop)]
public class SplashActivity : AppCompatActivity
{
public override void OnCreate(Bundle savedInstanceState, PersistableBundle persistentState)
{
base.OnCreate(savedInstanceState, persistentState);
}
// Launches the startup task
protected override void OnResume()
{
base.OnResume();
StartActivity(new Intent(Application.Context, typeof(MainActivity)));
}
public override void OnBackPressed() { }
}
On the MainActivty class, set its LaunchMode to SingleTop so the OS will reuse the activity IF it is all already running vs. starting a new one:
[Activity(Label = "Your Xamarin Forms App", MainLauncher = true, Icon = "#mipmap/icon", LaunchMode = Android.Content.PM.LaunchMode.SingleTop)]
NOTE: There are two entry points into MainActvity for the notification intent
a. If the activity is already running, OnNewIntent will be called with the intent that you setup on the notification.
b. If your app is not running, MainActvity will be created as a normal startup but will include the intent from from the notification, so check the intent in the OnCreate.
Related
in my Xamarin.Forms project I use OneSignal for notifications. In iOS Xamarin.Forms.Application.Current.MainPage = new NavigationPage(new NotificationPage()); worked but in Android this not work. I tried to use messaging center to communicate with PCL project. It worked when app is background but not working when app is closed. How can I redirect notification specific page when notification received in Android? Thanks
Note : Code edited and issue solved, I used shared preferences to control if app launched from notification or not. Then I Load xamarin.Forms application.
You can use below method before LoadApplication() method is called.
if (Intent.Extras != null)
{
foreach (var key in Intent.Extras.KeySet())
{
if (key != null)
{
var value = Intent.Extras.GetString(key);
Log.Debug(TAG, "Key: {0} Value: {1}", key, value);
}
}
}
LoadApplication(new App());
You have to set intent.putExtra() method in OnMessageReceivedMethod().
intent.PutExtra("Key", "value");
Then you can use redirection in App.xaml.cs file based on this key value. Because in android when notification is open while app is reinitialized.
I think you don't need to put below condition.
if (extrasList[0] == "true")
{
LoadApplication(new App(true));
}
else
{
LoadApplication(new App(false));
}
First Store your value global level so you can use it in App.cs file. Just use below code to handle page navigation in App() class like.
if (Device.RuntimePlatform == Device.Android)
{
if (YourKey == "true")
{
//handle that page navigation
}
else
{
//Default Page of App
}
}
Note : Code edited and issue solved, I used shared preferences to control if app launched from notification or not. Then I Load xamarin.Forms application
public class MainActivity :
global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
InitializeUI();
global::Xamarin.Forms.Forms.Init(this, bundle);
global::Xamarin.FormsMaps.Init(this, bundle);
ImageCircleRenderer.Init();
tV = new TextView(this);
resources = this.Resources;
OneSignal.Current.StartInit("***APP ID***")
.InFocusDisplaying(OSInFocusDisplayOption.Notification)
.HandleNotificationReceived(HandleNotificationReceived)
.HandleNotificationOpened(HandleNotificationOpened)
.EndInit();
ISharedPreferences prefs = PreferenceManager.GetDefaultSharedPreferences(this);
var LaunchFromNotification = prefs.GetString("is_notification_received", "false");
if (LaunchFromNotification == "true")
{
LoadApplication(new App(true));
}
else
{
LoadApplication(new App(false));
}
OneSignal.Current.IdsAvailable(IdsAvailable); //Lets you retrieve the OneSignal player id and push token.
}
}
private static void HandleNotificationOpened(OSNotificationOpenedResult result)
{
ISharedPreferences prefs = PreferenceManager.GetDefaultSharedPreferences(Android.App.Application.Context);
ISharedPreferencesEditor editor = prefs.Edit();
editor.PutString("is_notification_received", "true");
editor.Apply();
}
protected override void OnResume()
{
base.OnResume();
ISharedPreferences prefs =
PreferenceManager.GetDefaultSharedPreferences(this);
ISharedPreferencesEditor editor = prefs.Edit();
editor.Remove("is_notification_received");
editor.PutString("is_notification_received", "false");
editor.Apply();
}
I need to call a Xamarin.Forms Page through an Activity in Xamarin.Android.
I had used [Java.Interop.Export("btnOne1Click")] to call the Xamarin.Forms Page.
The code runs without errors if I use App.Current.MainPage = new RootPage(); But it does not navigate to that Page.
I don't want to call the [Java.Interop.Export("btnOne1Click")] on MainActivity.
[Activity(Label = "FailureActivity")]
public class FailureActivity : Activity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
RequestWindowFeature(WindowFeatures.NoTitle);
SetContentView(Resource.Layout.Failure);
Button button = FindViewById<Button>(Resource.Id.txt_go_onjobs);
}
[Java.Interop.Export("btnOne1Click")]
public void btnOne1Click(Android.Views.View v)
{
try
{
Xamarin.Forms.Forms.Context.StartActivity(typeof(RootPage));
}
catch(Exception ex)
{ }
}
}
Xamarin forms runs on one activity, which is most like your main activity.
There are two sample projects that show you how to communicate between native and form parts of the code, which can be found here:
https://github.com/xamarin/xamarin-forms-samples/tree/master/Forms2Native
https://github.com/xamarin/xamarin-forms-samples/tree/master/Native2Forms
However, to answer your question, you would do something like the following:
button = FindViewById<Button> (Resource.Id.txt_go_onjobs);
button.Click += (sender, e) => {
// this is your Xamarin.Forms screen
StartActivity(typeof(FormsActivity));
};
Now, in your FormsActivity call this:
[Activity (Label = "FormsActivity")]
public class FormsActivity : Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
protected override void OnCreate (Bundle bundle)
{
base.OnCreate (bundle);
Xamarin.Forms.Forms.Init (this, bundle);
LoadApplication (new App ());
}
}
I am using a custom button renderer for google sign In in xamarin forms page its working fine I get the signin resultin MainActivity Now i want to send this data from MainActivity and AppDelegate to the Particular page in Xamarin Forms.
protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
base.OnActivityResult(requestCode, resultCode, data);
if (requestCode == 9001)
{
Utilities.Configuration.UpdateConfigValue(Utilities.Constants.loggedInflag,string.Empty);
GoogleSignInResult result = Android.Gms.Auth.Api.Auth.GoogleSignInApi.GetSignInResultFromIntent(data);
if (result.IsSuccess)
{
GoogleSignInAccount acct = result.SignInAccount;
var token = acct.IdToken;
//I wan to send the 'accnt' to a Page in xamarin forms
}
else
{
//Signin Failure send response to Page in xamarin forms
}
}
}
Xamarin.Forms runs only in one Activity on Android. So if your url request comes out in a different Activity, you have to switch back to the MainActivity before you can use the normal XF navigation.
I do this when a user opens a file associated with my app.
[Activity(Label = "LaunchFileActivity")]
public class LaunchFileActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
if (Intent.Data != null)
{
var uri = Intent.Data;
if (uri != null)
{
Intent i = new Intent(this, typeof(MainActivity));
i.AddFlags(ActivityFlags.ReorderToFront);
i.PutExtra("fileName", uri.Path);
this.StartActivity(i);
}
}
this.FinishActivity(0);
}
}
And in MainActivity:
protected override void OnNewIntent(Intent intent)
{
base.OnNewIntent(intent);
Intent = intent;
}
protected override void OnPostResume()
{
base.OnPostResume();
if (Intent.Extras != null)
{
string fileName = Intent.Extras.GetString("fileName");
if (!string.IsNullOrEmpty(fileName))
{
// do something with fileName
}
Intent.RemoveExtra("fileName");
}
}
Xamarin forms runs on one activity, which is most like your main activity.
There are two sample projects that show you how to communicate between native and form parts of the code, which can be found here
https://github.com/xamarin/xamarin-forms-samples/tree/master/Forms2Native
https://github.com/xamarin/xamarin-forms-samples/tree/master/Native2Forms
However, to answer your question, you would do something like the following
private const int MyRequestCode = 101;
//Start activity for result
var contactPickerIntent = new Intent(Intent.ActionPick, Android.Provider.ContactsContract.Contacts.ContentUri);
context.StartActivityForResult(contactPickerIntent, MyRequestCode);
and then in your main activity (the activity that initializes your xamarin forms application (using global::Xamarin.Forms.Forms.Init(this, bundle);)
protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
if (requestCode == MyRequestCode && resultCode == Result.Ok)
{
}
}
I'm using the library https://github.com/aritchie/notifications and I can create and schedule notifications properly.
I wish to process them in Android so that depending on the notification - it will navigate to a particular page when the user taps on it.
I've found that the below event is fired when I tap on a notification (in my Android Project)
protected override void OnNewIntent(Intent intent)
{
}
However, I can't find any info in the intent from my notification in order to build up navigation to a particular page.
Any advice would be appreciated.
Cheers!
Edit #1 (Adding additional code for a related issue):
If I fire off a notification, and close the app before the notification is received - I receive an error saying the app has crashed. If I receive the notification and close the app - I can load the app from the notification OK.
I have a dependency service which hits the following methods.
public void Remind(DateTime dateTime, string msgtype, string usermedid)
{
DateTime now = DateTime.Now;
var diffinseconds = (dateTime - now).TotalSeconds;
Intent alarmIntent = new Intent(Forms.Context, typeof(AlarmBroadcastReceiver));
alarmIntent.PutExtra("notificationtype", msgtype);
alarmIntent.PutExtra("id", id);
PendingIntent pendingIntent = PendingIntent.GetBroadcast(Forms.Context, 0, alarmIntent, PendingIntentFlags.UpdateCurrent);
AlarmManager alarmManager = (AlarmManager)Forms.Context.GetSystemService(Context.AlarmService);
//TODO: For demo set after 5 seconds.
alarmManager.Set(AlarmType.ElapsedRealtime, SystemClock.ElapsedRealtime() + diffinseconds * 1000, pendingIntent);
}
[BroadcastReceiver(Enabled = true)]
[IntentFilter(new string[]{"android.intent.action.BOOT_COMPLETED"}, Priority = (int) IntentFilterPriority.LowPriority)]
public class AlarmBroadcastReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
string notificationtype = intent.GetStringExtra("notificationtype");
PowerManager.WakeLock sWakeLock;
var pm = PowerManager.FromContext(context);
sWakeLock = pm.NewWakeLock(WakeLockFlags.Partial, "GCM Broadcast Reciever Tag");
sWakeLock.Acquire();
intent = new Intent(Forms.Context, typeof(MainActivity));
intent.PutExtra("notificationtype", notificationtype);
intent.AddFlags(ActivityFlags.IncludeStoppedPackages);
// Instantiate the builder and set notification elements, including pending intent:
NotificationCompat.Builder builder = new NotificationCompat.Builder(Forms.Context)
.SetDefaults((int)NotificationDefaults.Sound | (int)NotificationDefaults.Vibrate)
.SetAutoCancel(true)
.SetContentIntent(PendingIntent.GetActivity(Forms.Context, 0, intent, 0)).SetContentTitle("Sample Notification")
.SetContentText("Hello World! This is my first action notification!")
.SetTicker("New Notification")
.SetSmallIcon(Resource.Drawable.icon);
// Build the notification:
Android.App.Notification notification = builder.Build();
notification.Flags = NotificationFlags.AutoCancel;
// Get the notification manager:
//NotificationManager notificationManager = Forms.Context.GetSystemService(Context.NotificationService) as NotificationManager;
var manager = NotificationManagerCompat.From(context);
// Publish the notification:
const int notificationId = 0;
manager.Notify(notificationId, notification);
sWakeLock.Release();
}
}
How do I keep my Broadcast Receiver alive when the app is closed?
Ok so it took me some time to figure this one out. OnNewIntent is called when the app is in the background and the notification is clicked on. It is also called each time the app is minimized and the brought back up... so to tell the difference between the 2 events, you need to check the passed in Intent for what extra data is inside it. The extra data would have come from the Intent you made when you first initiated the notification.
Also make sure to set your MainActivity's LaunchMode to LaunchMode.SingleTop so that your app does not get restarted each time the notification is clicked on.
[Activity(LaunchMode = LaunchMode.SingleTop, ....)]
public class MainActivity : FormsApplicationActivity {
....
/// <summary>
/// Called when the app is in the background and a notification is clicked on (also called each time the app is minimized and the brought back up), a new <c>Intent</c> is created
/// and sent out, since we use <c>LaunchMode</c> set to <c>SingleTop</c> this method is called instead of the app being restarted.
/// </summary>
/// <param name="intent">The <c>Intent</c> that was set when the call was made. If started from a notification click, extra <c>string</c> values can be extracted.</param>
protected override void OnNewIntent(Intent intent) {
if(intent.HasExtra("Some special key you made up")) { //Here is where you check for special notification intent extras
//Do something brilliant now that you know a notification was clicked on
}
base.OnNewIntent(intent);
}
To see how you can add data to the Intent you can check out the Xamarin Sport App, but do not get too bogged down in all the other stuff they are doing like I always tend to do. Just focus on the PutExtra part.
Edit #1:
If your app is completely closed, you need to pull the data from the Intent passed into OnCreate and pass it into your App class or do something else with it:
protected override async void OnCreate(Android.OS.Bundle bundle) {
base.OnCreate(bundle);
Forms.Init(this, bundle);
string parameterValue = Intent.GetStringExtra("Some special key you made up"); //This would come in from the Push Notification being clicked on
Console.WriteLine("\nIn MainActivity.OnCreate() - Param Intent Extras: {0}\n", parameterValue);
//MessagingCenter.Send("nothing", ConstantKeys.NewNotification); //Do something special with the notification data
LoadApplication(parameterValue != null ? new App(parameterValue) : new App()); //Do something special with the notification data
}
Edit #2:
Some changes I would recommend to your OnReceive method based on my current code (some may not be necessary, but it is just what I am doing):
Label your Broadcast Receiver
Add stupid Xamarin constructors
Used constant property instead of string for IntentFilter
Remove IntentFilter Priority
Check for null Intent (might not be necessary)
Use Application.Context instead of Forms.Context (I use Forms.Context in other parts of my app so not sure about this one, but
can't hurt)
Do not overwrite the passed in Intent
Create startup intent instead of regular
Add IncludeStoppedPackages flag before pulling out extras
Check for boot completed event
Use Notification.Builder instead of NotificationCompat.Builder (though you might need to change this back)
Add following flags to pendingintent: PendingIntentFlags.UpdateCurrent | PendingIntentFlags.OneShot
-- Use NotificationManager (unless you have a specific reason you commented it out)
[assembly: UsesPermission(Android.Manifest.Permission.Vibrate)]
[assembly: UsesPermission(Android.Manifest.Permission.WakeLock)] //Optional, keeps the processor from sleeping when a message is received
[assembly: UsesPermission(Android.Manifest.Permission.ReceiveBootCompleted)] //Allows our app to be opened and to process notifications even when the app is closed
namespace Your.App.Namespace {
[BroadcastReceiver(Enabled = true, Label = "GCM Alarm Notifications Broadcast Receiver")]
[IntentFilter(new []{ Intent.ActionBootCompleted })]
public class AlarmBroadcastReceiver : BroadcastReceiver {
#region Constructors
// ReSharper disable UnusedMember.Global
public AlarmBroadcastReceiver() { }
public AlarmBroadcastReceiver(IntPtr handle, JniHandleOwnership transfer) : base(handle, transfer) { }
// ReSharper restore UnusedMember.Global
#endregion
public void Remind(DateTime dateTime, string msgtype, string usermedid) {
DateTime now = DateTime.Now;
var diffinseconds = (dateTime - now).TotalSeconds;
Intent alarmIntent = new Intent(Application.Context, typeof(AlarmBroadcastReceiver));
alarmIntent.PutExtra("notificationtype", msgtype);
alarmIntent.PutExtra("id", id);
PendingIntent pendingIntent = PendingIntent.GetBroadcast(Application.Context, 0, alarmIntent, PendingIntentFlags.UpdateCurrent);
AlarmManager alarmManager = (AlarmManager)Application.Context.GetSystemService(Context.AlarmService);
//TODO: For demo set after 5 seconds.
alarmManager.Set(AlarmType.ElapsedRealtime, SystemClock.ElapsedRealtime() + diffinseconds * 1000, pendingIntent);
}
public override void OnReceive(Context context, Intent intent) {
#region Null Check
if(intent == null) {
Console.WriteLine("\nIn AlarmBroadcastReceiver.OnReceive() - Intent is null\n");
return;
}
#endregion
intent.AddFlags(ActivityFlags.IncludeStoppedPackages);
string action = intent.Action;
Console.WriteLine("\nIn AlarmBroadcastReceiver.OnReceive() - Action: {0}\n", action);
#region Boot Completed Check
if(action.Equals("android.intent.action.BOOT_COMPLETED")) {
PowerManager pm = PowerManager.FromContext(context);
PowerManager.WakeLock sWakeLock = pm.NewWakeLock(WakeLockFlags.Partial, "GCM Broadcast Receiver Tag");
sWakeLock.Acquire();
Console.WriteLine("\nIn AlarmBroadcastReceiver.OnReceive() - Process Shared Preferences Notifications\n");
#region Process Saved Scheduled Notifications
//Get list of saved scheduled notifications that did not fire off before the device was turned off (I store them in SharedPreferences and delete them after they are fired off)
//Go through the list and reschedule them
#endregion
sWakeLock.Release();
return;
}
#endregion
string notificationtype = intent.GetStringExtra("notificationtype");
Intent startupIntent = Application.Context.PackageManager.GetLaunchIntentForPackage(Application.Context.PackageName);
startupIntent.PutExtra("notificationtype", notificationtype);
// Instantiate the builder and set notification elements, including pending intent:
Notification.Builder builder = new Notification.Builder(Application.Context)
.SetDefaults((int)NotificationDefaults.Sound | (int)NotificationDefaults.Vibrate)
.SetAutoCancel(true)
.SetContentIntent(PendingIntent.GetActivity(Application.Context, 0, intent, PendingIntentFlags.UpdateCurrent | PendingIntentFlags.OneShot))
.SetContentTitle("Sample Notification")
.SetContentText("Hello World! This is my first action notification!")
.SetTicker("New Notification")
.SetSmallIcon(Resource.Drawable.icon);
// Build the notification:
Android.App.Notification notification = builder.Build();
// Get the notification manager:
NotificationManager notificationManager = Application.Context.GetSystemService(Context.NotificationService) as NotificationManager;
// Publish the notification:
int notificationId = ??;//This should be a real unique number, otherwise it can cause problems if there are ever multiple scheduled notifications
notificationManager.Notify(notificationId, notification);
}
}
}
I'm currently working on a Xamarin application working both on iOS and Android, but the problem I'm going to explain only concerns the Android application (this is not yet implemented in the iOS app).
Actually, when I receive a given push notification, I need to open a specific page in my application. It works very well if the application is open when the push notification is received, but the app crashes if my app is closed or run in background.
Well, when I receive the notification, I end up in the method called "OnShouldOpenCommand" :
private void OnShouldOpenCommand(string commandId)
{
NotifyNewCommand(AppResources.AppName, AppResources.CommandNotificationText, commandId);
Device.BeginInvokeOnMainThread(() =>
{
try
{
App.MasterDetailPage.Detail = new NavigationPage(new CommandAcceptancePage(commandId))
{
BarBackgroundColor = Color.FromHex("1e1d1d")
};
App.MasterDetailPage.NavigationStack.Push(((NavigationPage)(App.MasterDetailPage.Detail)).CurrentPage);
}
catch(Exception e)
{
Log.Debug("PushAsync", "Unable to push CommandAcceptancePage : "+ex.Message);
}
});
}
private void NotifyNewCommand(string Title,string Description, string commandId)
{
var intent = new Intent(this, typeof(MainActivity));
if (!String.IsNullOrEmpty(commandId))
{
intent.PutExtra("CommandId", commandId);
}
intent.AddFlags(ActivityFlags.ClearTop);
var pendingIntent = PendingIntent.GetActivity(this, 0, intent, 0);
var notificationBuilder = new Notification.Builder(this)
.SetSmallIcon(Resource.Drawable.icon)
.SetContentTitle("Kluox")
.SetContentText(Description)
.SetAutoCancel(true)
.SetContentIntent(pendingIntent);
Notification notification = notificationBuilder.Build();
var notificationManager = (NotificationManager)GetSystemService(Context.NotificationService);
notificationManager.Notify(0, notification);
}
And the code
App.MasterDetailPage.Detail = new NavigationPage(new CommandAcceptancePage(commandId))
{
BarBackgroundColor = Color.FromHex("1e1d1d")
};
is generating an exception of type :
Java.Lang.IllegalStateException: Can not perform this action after
onSaveInstanceState
So well, I suppose I can't access "App" and redirect to another page if my application is not running in foreground. Well, this is when I receive the push notification an not when I click on it. But well, I do not intend to reopen my app by doing this.
Because afther that, when I click on the push notification called Kluox (and this is supposed to reopen my app), the app crashes and I really don't know why, I don't know where to put breakpoints to be able to debug because Visual Studio just tells me "An unhandled exception occured.".
Could anyone help me ? If you need any piece of code, you can just ask me, I'll edit my message and give you any information you need !
EDIT 1 : Here is the code of my OnCreate method :
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
var info = Intent.Extras?.GetString("CommandId", "");
global::Xamarin.Forms.Forms.Init(this, bundle);
if (String.IsNullOrEmpty(info))
{
LoadApplication(new App());
}
else
{
LoadApplication(new App(info));
}
if (instance == null)
{
instance = this;
RegisterWithGCM();
}
else
{
instance = this;
}
}
After overriding all the methods of MainActivity, I finally found the cause of the crash : the method OnDestroy was called twice, and threw a IllegalStateException because the activity was already destroyed. I found this workaround :
protected override void OnDestroy()
{
try
{
base.OnDestroy();
}
catch (Java.Lang.IllegalStateException ex)
{
Log.Debug("MainActivity.OnDestroy", ex, "The activity was destroyed twice");
}
}
And the exception is simply logged, the application can open and be used without problems.
I'll edit this answer when the redirection works too.
EDIT : how to redirect to a page
First, we needed to register for the MessagingCenter, in the constructor
public static MyPackage.Model.Command CurrentCommand { get; set; }
public App()
{
InitializeComponent();
MainPage = new ContentPage();
MessagingCenter.Subscribe<object, DataLib.Model.Command>(this, "Command", (sender, arg) => {
try
{
CurrentCommand = arg;
}
catch(Exception ex)
{
CurrentCommand = null;
}
});
}
And send the message when we get the push notification :
private void OnMessage(string serializedCommand)
{
//stuff happens
MessagingCenter.Send<object, MyPackage.Model.Command>(this, "Command", command);
}
Finally, when we get the OnStart() of App.Xaml.cs
if (CurrentCommand != null)
{
App.MasterDetailPage.Detail = new NavigationPage(new CommandAcceptancePage(CurrentCommand, service))
{
BarBackgroundColor = Color.FromHex("1e1d1d")
};
}
For now, it seems to do the trick ! More debugging will follow, but the code seems to work. Thanks a VERY lot to #BraveHeart for their help !
well luckily for you I was there few days ago and lost a lot of hair till I got it working in Android (and still in the strugle for iOS).
When you kill your app and instantiate it again form the icon or from the notification in both cases you will go to the main activity .
If we want to take some information in the main activity from the notification that instantiated it we do it like this in OnCreate():
var info = Intent.Extras?.GetString("info", "");
Now in your case I would add extra information to the notification showing that which View/Page this notification is about, something like the name of it for example)
This extra piece of information you can pass it to the constructor of the App before you load it.
In the constructor of the app you can check if there are extra info or not , if not that means to start the app's mainPage is the default MainPage, otherwise it is a certain page.