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.Net Core 3.1 using GraphQLHttpClient from C#/WPF gets stuck - but works with ConsoleApp

I have created a small GraphQl server - that is working very nicely from Banana Cake Pop.
Then I have created a small C#/.Net Core 3.1 WPF App - that has a Class Library that uses GraphQL.Client 3.2.2 and GraphQL.Client.Serializer.Newtonsoft 3.2.2
It also has a class like this to call the GraphQL Endpoint:
public class RepositoryBase
{
protected GraphQLHttpClient GraphQLHttpClient { get; private set; }
public RepositoryBase()
{
GraphQLHttpClient = new GraphQLHttpClient("http://xxx/graphql/",
new NewtonsoftJsonSerializer());
}
}
public class ArtRepository : RepositoryBase
{
public List<Art> GetArterByGruppe(short GruppeId)
{
var queryString = #"query { arter(where: { and:[{ gruppeId: { eq: 1200} } { su: { eq: false} } { setIDk: { eq: true} }]}
order: {artNavn:ASC}) {
artNavn
artId
gruppe {
gruppeNavn
gruppeId
}
}
}";
var request = new GraphQLRequest
{
Query = queryString
};
var result = GraphQLHttpClient.SendQueryAsync<ArtResponse>(request).ConfigureAwait(false);
return result.GetAwaiter().GetResult().Data.Arter;
}
}
If I call this method from the WPF App - like in the Windows Loaded event - the call to the GrapQl Server gets stuck - with no errros.
var repository = new ArtRepository();
var x = repository.GetArterByGruppe(1700);
So - in dispair - I created a ConsoleApp project in the WPF solution - that makes the same call to the ArtRepository Class - and it just runs very fine and returns data.
I don't understand how the WPF App can influence the GraphQL client in a way that it get's stuck?

Acumatica mobile push notification without using Business Event

How do I send mobile push notification without using Business Event ?

It is possible to send mobile push notification without using Business Events to open screen in mobile application when user taps the notification.
Below example describes approach :
using System;
using System.Collections;
using System.Linq;
using System.Threading;
using CommonServiceLocator;
using PX.Api.Mobile.PushNotifications;
using PX.Common;
using PX.Data;
using PX.Objects.SO;
namespace PX.PushNotificatioinSample.Ext
{
public class SOOrderEntryPXExt : PXGraphExtension<SOOrderEntry>
{
public PXAction<SOOrder> ViewOnMobileApp;
[PXUIField(DisplayName = Messages.ViewActionDisplayName,
MapEnableRights = PXCacheRights.Select, MapViewRights = PXCacheRights.Select)]
[PXButton(SpecialType = PXSpecialButtonType.Default)]
public virtual IEnumerable viewOnMobileApp(PXAdapter adapter)
{
if (Base.Document.Cache.GetStatus(Base.Document.Current) == PXEntryStatus.Inserted ||
Base.Document.Cache.GetStatus(Base.Document.Current) == PXEntryStatus.InsertedDeleted) { return adapter.Get(); }
//Get instance of PushNotification service
var pushNotificationSender = ServiceLocator.Current.GetInstance<IPushNotificationSender>();
//Users to whom message will be sent
var userIds = new[] { PXAccess.GetUserID() };
//Check if User is using Acumatica Mobile App
var activeTokens = pushNotificationSender.CountActiveTokens(userIds);
if (activeTokens == 0)
{
throw new PXException(Messages.NoDeviceError);
}
string sOrderNbr = Base.Document.Current.OrderNbr;
string sScreenID = Base.Accessinfo.ScreenID.Replace(".", "");
Guid noteID = Base.Document.Current.NoteID.Value;
PXLongOperation.StartOperation(Base, () =>
{
try
{
pushNotificationSender.SendNotificationAsync(
userIds: userIds,
// Push Notification Title
title: Messages.PushNotificationTitle,
// Push Notification Message Body
text: $"{ Messages.PushNotificationMessageBody } { sOrderNbr }.",
// Link to Screen to open upon tap with Sales Order data associated to NoteID
link: (sScreenID, noteID),
cancellation: CancellationToken.None);
}
catch (AggregateException ex)
{
var message = string.Join(";", ex.InnerExceptions.Select(c => c.Message));
throw new InvalidOperationException(message);
}
});
return adapter.Get();
}
}
[PXLocalizable]
public static class Messages
{
public const string ViewActionDisplayName = "View On Mobile App";
public const string NoDeviceError = "You need to set up the Acumatica mobile app.";
public const string PushNotificationTitle = "View Sales Order";
public const string PushNotificationMessageBody = "Tap to view Sales Order # ";
}
}

Actionable push notification in Xamarin iOS

var acceptAction = UNNotificationAction.FromIdentifier("AcceptAction", "Accept", UNNotificationActionOptions.None);
var declineAction = UNNotificationAction.FromIdentifier("DeclineAction", "Decline", UNNotificationActionOptions.None);
// Create category
var meetingInviteCategory = UNNotificationCategory.FromIdentifier("MeetingInvitation",
new UNNotificationAction[] { acceptAction, declineAction }, new string[] { }, UNNotificationCategoryOptions.CustomDismissAction);
// Register category
var categories = new UNNotificationCategory[] { meetingInviteCategory };
UNUserNotificationCenter.Current.SetNotificationCategories(new NSSet<UNNotificationCategory>(categories));
how can you receive a custom actionable push notification and where need to put the above code in which file?

Before an iOS app can send notifications to the user the app must be registered with the system and, because a notification is an interruption to the user, an app must explicitly request permission before sending them.
Notification permission should be requested as soon as the app launches by adding the following code to the FinishedLaunching method of the AppDelegate and setting the desired notification type (UNAuthorizationOptions):
...
using UserNotifications;
...
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
....
//after iOS 10
if(UIDevice.CurrentDevice.CheckSystemVersion(10,0))
{
UNUserNotificationCenter center = UNUserNotificationCenter.Current;
center.RequestAuthorization(UNAuthorizationOptions.Alert | UNAuthorizationOptions.Sound | UNAuthorizationOptions.UNAuthorizationOptions.Badge, (bool arg1, NSError arg2) =>
{
});
center.Delegate = new NotificationDelegate();
}
else if(UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
var settings = UIUserNotificationSettings.GetSettingsForTypes(UIUserNotificationType.Alert| UIUserNotificationType.Badge| UIUserNotificationType.Sound,new NSSet());
UIApplication.SharedApplication.RegisterUserNotificationSettings(settings);
}
return true;
}
New to iOS 10, an app can handle Notifications differently when it is in the foreground and a Notification is triggered. By providing aUNUserNotificationCenterDelegate and implementing theUserNotificationCentermethod, the app can take over responsibility for displaying the Notification. For example:
using System;
using ObjCRuntime;
using UserNotifications;
namespace xxx
{
public class NotificationDelegate:UNUserNotificationCenterDelegate
{
public NotificationDelegate()
{
}
public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
{
// Do something with the notification
Console.WriteLine("Active Notification: {0}", notification);
// Tell system to display the notification anyway or use
// `None` to say we have handled the display locally.
completionHandler(UNNotificationPresentationOptions.Alert|UNNotificationPresentationOptions.Sound);
}
public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
{
// Take action based on Action ID
switch (response.ActionIdentifier)
{
case "reply":
// Do something
break;
default:
// Take action based on identifier
if (response.IsDefaultAction)
{
// Handle default action...
}
else if (response.IsDismissAction)
{
// Handle dismiss action
}
break;
}
// Inform caller it has been handled
completionHandler();
}
}
}

Login Screen before Master Detail View in Xamarin

I am trying to write a xamarin app that will display a login page before a master detail page but I am running into issues.
Right now I have my app.xaml calling an appbootstrapper as follows:
public App()
{
this.InitializeComponent();
RxApp.SuspensionHost.CreateNewAppState = () => new AppBootstrapper();
RxApp.SuspensionHost.SetupDefaultSuspendResume();
this.MainPage = RxApp.SuspensionHost
.GetAppState<AppBootstrapper>()
.CreateMainPage();
}
/// <summary>Gets the Router associated with this Screen.</summary>
public RoutingState Router { get; } = new RoutingState();
With the app bootstrapper as follows:
public class AppBootstrapper : ReactiveObject, IScreen
{
public AppBootstrapper(IMutableDependencyResolver dependencyResolver = null)
{
SetupLogging();
this.RegisterParts(dependencyResolver ?? Locator.CurrentMutable);
this.Router.Navigate.Execute(new LoginPageViewModel(this));
}
/// <summary>Gets the Router associated with this Screen.</summary>
public RoutingState Router { get; } = new RoutingState();
public Page CreateMainPage()
{
return new RoutedViewHost();
}
private static void SetupLogging()
{
var logger = new Logger { Level = LogLevel.Debug };
Locator.CurrentMutable.RegisterConstant(logger, typeof(ILogger));
}
private void RegisterParts(IMutableDependencyResolver dependencyResolver)
{
dependencyResolver.RegisterConstant(this, typeof(IScreen));
dependencyResolver.Register(() => new LoginPage(), typeof(IViewFor<LoginPageViewModel>));
dependencyResolver.RegisterConstant(new LoginService(), typeof(ILoginService));
}
}
This gets me to my login screen no problem, and I can perform my login operation. Then, once login is successful, I try to navigate to the master detail page, but this is where I run into issues.
public LoginPageViewModel(IScreen screen)
{
this.loginService = Locator.Current.GetService<ILoginService>();
this.HostScreen = screen ?? Locator.Current.GetService<IScreen>();
this.PrepareObservables();
}
........................................................
private void PrepareObservables()
{
...
this.LoginCommand = ReactiveCommand.CreateFromTask(
async execute =>
{
var loginSuccessful = await this.loginService.Login(this.Username, this.Password);
if (loginSuccessful)
{
this.HostScreen.Router.NavigateBack.Execute().Subscribe();
}
}, canExecuteLogin);
...
You can see that my login command is trying to perform a navigate and reset to go to the Main Page (which is my master detail page). This is not working and is resulting in an unhandled exception stating:
An object implementing IHandleObservableErrors has errored, thereby breaking its observable pipeline. To prevent this, ...>
Does anyone know what to do here? I need a good pattern for handling the use case of Login -> Master Detail Page in Xamarin Forms using ReactiveUI. Thanks.

this.LoginCommand = ReactiveCommand.CreateFromTask(
async execute =>
{
var loginSuccessful = await this.loginService.Login(this.Username, this.Password);
if (loginSuccessful)
{
this.HostScreen.Router.NavigateBack.Execute().Subscribe();
}
}, canExecuteLogin);
The above code is navigating back on successful login. I think you mean to use Router.NavigateAndReset.Execute(new MainPageViewModel()).Subscribe();

Have I set up my Android push notifications correctly?

I am setting up push notifications in my Xamarin Forms app for my Android project. I have been following the online documentation (https://developer.xamarin.com/guides/xamarin-forms/cloud-services/push-notifications/azure/) to get it working but I am having some problems
1 - The notifications don't arrive when I send a test from my Azure Notification Hub.
2 - The app crashes during debug after a certain amount of time during the Register method.
I believe that the problem is being caused by its registration, I don't think the registration is working and hence the app times out which causes it to crash and also the Azure Notification Hub sends the message successfully but no device picks it up (possibly because it's not registred)
To start off, here is what I have done so far.
I have setup a project in console.firebase.google.com and taken note of the sender ID and the Server Key as instructed. I have given the Project ID a name of myapp-android-app.
I have added all the code from the documtation to my Android project.
I have added a GCM notification service to my Notification Hub in Azure and supplied it with the Server Key documented from my Firebase app registration.
I have added my google account to my Andoird Emulator
Here is the source code from my Android project.
MainActivity.cs
using System;
using Android.App;
using Android.Content.PM;
using Android.OS;
using Gcm.Client;
namespace MyApp.Droid
{
[Activity(Label = "#string/app_name", Theme = "#style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
//public static MainActivity CurrentActivity { get; private set; }
// Create a new instance field for this activity.
static MainActivity instance = null;
// Return the current activity instance.
public static MainActivity CurrentActivity
{
get
{
return instance;
}
}
protected override void OnCreate(Bundle bundle)
{
instance = this;
base.OnCreate(bundle);
global::Xamarin.Forms.Forms.Init(this, bundle);
Microsoft.WindowsAzure.MobileServices.CurrentPlatform.Init();
LoadApplication(new App());
try
{
// Check to ensure everything's setup right
GcmClient.CheckDevice(this);
GcmClient.CheckManifest(this);
// Register for push notifications
System.Diagnostics.Debug.WriteLine("Registering...");
GcmClient.Register(this, PushHandlerBroadcastReceiver.SENDER_IDS);
}
catch (Java.Net.MalformedURLException)
{
CreateAndShowDialog("There was an error creating the client. Verify the URL.", "Error");
}
catch (Exception e)
{
CreateAndShowDialog(e.Message, "Error");
}
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
}
void CreateAndShowDialog(String message, String title)
{
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.SetMessage(message);
builder.SetTitle(title);
builder.Create().Show();
}
}
}
GcmService.cs
using Android.App;
using Android.Content;
using Android.Media;
using Android.Support.V4.App;
using Android.Util;
using Gcm.Client;
using Microsoft.WindowsAzure.MobileServices;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
[assembly: Permission(Name = "#PACKAGE_NAME#.permission.C2D_MESSAGE")]
[assembly: UsesPermission(Name = "#PACKAGE_NAME#.permission.C2D_MESSAGE")]
[assembly: UsesPermission(Name = "com.google.android.c2dm.permission.RECEIVE")]
[assembly: UsesPermission(Name = "android.permission.INTERNET")]
[assembly: UsesPermission(Name = "android.permission.WAKE_LOCK")]
//GET_ACCOUNTS is only needed for android versions 4.0.3 and below
[assembly: UsesPermission(Name = "android.permission.GET_ACCOUNTS")]
namespace MyApp.Droid
{
[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 PushHandlerBroadcastReceiver : GcmBroadcastReceiverBase<GcmService>
{
public static string[] SENDER_IDS = new string[] { "xxxxxxxxxx" };
}
[Service]
public class GcmService : GcmServiceBase
{
public static string RegistrationToken { get; private set; }
public GcmService()
: base(PushHandlerBroadcastReceiver.SENDER_IDS) { }
protected override void OnRegistered(Context context, string registrationToken)
{
Log.Verbose("PushHandlerBroadcastReceiver", "GCM Registered: " + registrationToken);
RegistrationToken = registrationToken;
var push = AzureService.DefaultManager.CurrentClient.GetPush();
MainActivity.CurrentActivity.RunOnUiThread(() => Register(push, null));
}
protected override void OnUnRegistered(Context context, string registrationToken)
{
Log.Error("PushHandlerBroadcastReceiver", "Unregistered RegisterationToken: " + registrationToken);
}
protected override void OnError(Context context, string errorId)
{
Log.Error("PushHandlerBroadcastReceiver", "GCM Error: " + errorId);
}
public async void Register(Microsoft.WindowsAzure.MobileServices.Push push, IEnumerable<string> tags)
{
try
{
const string templateBodyGCM = "{\"data\":{\"message\":\"$(messageParam)\"}}";
JObject templates = new JObject();
templates["genericMessage"] = new JObject
{
{"body", templateBodyGCM}
};
await push.RegisterAsync(RegistrationToken, templates);
Log.Info("Push Installation Id", push.InstallationId.ToString());
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.Message + ex.StackTrace);
Debugger.Break();
}
}
protected override void OnMessage(Context context, Intent intent)
{
Log.Info("PushHandlerBroadcastReceiver", "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());
}
// Retrieve the message
var prefs = GetSharedPreferences(context.PackageName, FileCreationMode.Private);
var edit = prefs.Edit();
edit.PutString("last_msg", msg.ToString());
edit.Commit();
string message = intent.Extras.GetString("message");
if (!string.IsNullOrEmpty(message))
{
CreateNotification("New todo item!", "Todo item: " + message);
}
string msg2 = intent.Extras.GetString("msg");
if (!string.IsNullOrEmpty(msg2))
{
CreateNotification("New hub message!", msg2);
return;
}
CreateNotification("Unknown message details", msg.ToString());
}
void CreateNotification(string title, string desc)
{
// Create notification
var notificationManager = GetSystemService(Context.NotificationService) as NotificationManager;
// Create an intent to show the UI
var uiIntent = new Intent(this, typeof(MainActivity));
// Create the notification
// we use the pending intent, passing our ui intent over which will get called
// when the notification is tapped.
NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
var notification = builder.SetContentIntent(PendingIntent.GetActivity(this, 0, uiIntent, 0))
.SetSmallIcon(Android.Resource.Drawable.SymActionEmail)
.SetTicker(title)
.SetContentTitle(title)
.SetContentText(desc)
.SetSound(RingtoneManager.GetDefaultUri(RingtoneType.Notification)) // set the sound
.SetAutoCancel(true).Build(); // remove the notification once the user touches it
// Show the notification
notificationManager.Notify(1, notification);
}
}
}
I replaced the string in: public static string[] SENDER_IDS = new string[] { "xxxxxxxx" }; with the Sender id I recorded from my Firebase console app.
When I run the app through my Android Emulator I get the following error after about 3 minutes.
Error in GcmService.cs:
Exception: System.Threading.Tasks.TaskCanceledException: A task was canceled.
seen at Line 71:
await push.RegisterAsync(RegisteToken, templates);
Does anyone know what I have done wrong? Am I correct in thinking that it's not registering correctly?

I was able to integrate Firebase Cloud Messaging in Xamarin.Forms (both Android and iOS) following this official Xamarin guide that is well explained:
https://developer.xamarin.com/guides/android/application_fundamentals/notifications/remote-notifications-with-fcm/
Looking at your code, it seems to me that you use the old Gcm service (that is deprecated) and not the new Fcm.
You should have a google-services.json file and a FirebaseMessagingService class
Then...
Note
As of now, Xamarin Forms does not handle very well the deployment of the app while developing, making a dirty reinstallation that seems to invalidate the previously obtained Notification Token and sometimes raising IllegalStateException when calling Fcm library's methods.
That's a known bug that can be resolved by cleaning the solution and
relaunching