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I'm creating an event-management system. In this system I have a WCF service which loads the events. I have a layered architecture with a repository and service layer. The data is published to an Azure web service app. The data is consumed in a Xamarin.Forms application:

public class EventRepository : IEventRepository
    {
        public EventRepository()
        {
            InitializeEvents();
        }
        public List<Event> Events { get; set; }
        private void InitializeEvents()
        {
            if (Events == null)
            {
                Events = new List<Event>()
                {
                    new Event()
                    {
                        EventTitle = "Tom's 14th Birthday Party",
                        EventDescription = "Tom's celebrating his 14th birthday party, come and celebrate with us!",
                        EventGuid = Guid.Parse("258cfa9a-232a-4f36-8eec-010ad072ede3"),
                        Image = "https://external-content.duckduckgo.com/iu/?u=http%3A%2F%2Fimg.aws.livestrongcdn.com%2Fls-1200x630%2Fds-photo%2Fgetty%2Farticle%2F251%2F177%2F78054774.jpg&f=1&nofb=1",

                        Time = new TimeSpan(14, 30, 0),
                        Date = new DateTime(2021, 1, 2),
                        Area = "New York, NY",
                        Street = "5 Medburry Place"
                    },
                    new Event()
                    {
                        EventTitle = "Skate Event at Ownen's",
                        EventDescription = "Come to 52 Owen's Park and skate together with us!",
                        EventGuid = Guid.Parse("26ea384f-8fee-4455-8a5f-5b405e07e582"),
                        Image = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwesternnews.media.clients.ellingtoncms.com%2Fimg%2Fphotos%2F2017%2F06%2F11%2FSkate_Competition_002.jpg&f=1&nofb=1",
                                                
                        Time = new TimeSpan(8, 30, 0),
                        Date = new DateTime(2021, 3, 12),
                        Area = "Los Angeles, California",
                        Street = "8 Roland Avenue"
                    },
                    new Event()
                    {
                        EventTitle = "Teen Meetup Event",
                        EventDescription = "13-18 year olds - come to this event to meet other teens!",
                        EventGuid = Guid.Parse("ee39dfd5-f220-4111-8b49-bdf554dcce56"),
                        Image = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.thebostoncalendar.com%2Fsystem%2Fevents%2Fphotos%2F000%2F079%2F749%2Foriginal%2Ffellowship2015.jpg%3F1465380904&f=1&nofb=1",
                                               
                        Time = new TimeSpan(11, 0, 0),
                        Date = new DateTime(2021, 2, 5),
                        Area = "Sydney, Australia",
                        Street = "12 Sugar Place",
                    },
                    new Event()
                    {
                        EventTitle = "VIP Lamborghini Event",
                        EventDescription = "Have a lambo? Come to our event!",
                        EventGuid = Guid.Parse("5b7da478-a26c-4bee-8a9d-3bdb1318ed16"),
                        Image = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fag-log.o.auroraobjects.eu%2F04-2017%2Flamborghini_corsa%2F3.jpg&f=1&nofb=1",
                                                
                        Time = new TimeSpan(6, 0, 0),
                        Date = new DateTime(2021, 1, 8),
                        Area = "Los Angeles, California",
                        Street = "53 Rodeo Drive"
                    },
                    new Event()
                    {
                        EventTitle = "Jona's 18th Birthday Party",
                        EventDescription = "Jona's celebrating his 18th birthday party, come and celebrate with us!",
                        EventGuid = Guid.Parse("7aaca8b4-ae8d-4075-87cd-6dccc79d1018"),
                        Image = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fmirageparties.co.uk%2Fwp-content%2Fuploads%2F2019%2F01%2F18th-birthday-party-hero.jpg&f=1&nofb=1",
                                               
                        Time = new TimeSpan(17, 20, 0),
                        Date = new DateTime(2021, 1, 1),
                        Area = "Dunedin, New Zealand",
                        Street = "3 Bird Street"
                    }
                };

                Events[0].EventCode = Events[0].GenerateCode();
                Events[1].EventCode = Events[1].GenerateCode();
                Events[2].EventCode = Events[2].GenerateCode();
                Events[3].EventCode = Events[3].GenerateCode();
                Events[4].EventCode = Events[4].GenerateCode();
            }
        }
        public void AddEvent(Event @event)
        {
            @event.EventGuid = Guid.NewGuid();
            @event.Image = "https://static.wixstatic.com/media/be0a80_ab5136b10eec4badbf20309b90932e81.jpg";
            Events.Add(@event);
        }

        public IList<Event> GetAllEvents()
        {
            return Events;
        }
    }
public class EventService : IEventService
    {
        private readonly IEventRepository _eventRepository;
        public EventService(IEventRepository eventRepository)
        {
            _eventRepository = eventRepository;
        }

        public void AddEvent(Event @event)
        {
            _eventRepository.AddEvent(@event);
        }

        public IList<Event> GetAllEvents()
        {
            return _eventRepository.GetAllEvents();
        }
    }
 public class EventWCFService : IEventWCFService
    {
        private static IEventService _eventService = new EventService(new EventRepository());
        public void AddEvent(Event @event)
        {
            try
            {
                if (String.IsNullOrWhiteSpace(@event.EventTitle) || @event == null)
                {
                    throw new FaultException("Event name is required");
                }

                _eventService.AddEvent(@event);
            }
            catch (Exception exception)
            {
                throw new FaultException($"Whoops... Something has gone wrong {exception.Message}");
            }
        }
        public IList<Event> GetAllEvents()
        {
            return _eventService.GetAllEvents();
        }
    }

[ServiceContract]
    public interface IEventWCFService
    {
        [OperationContract]
        IList<Event> GetAllEvents();
        [OperationContract]
        void AddEvent(Event @event);
    }


Xamarin.Forms:

public class EventRepository : IEventRepository
    {
        private readonly ServiceReference1.IEventWCFService eventWCFService;
        public static readonly EndpointAddress EndPoint = new EndpointAddress("(my address)"); // Azure endpoint address
        public EventRepository()
        {
            eventWCFService = new ServiceReference1.EventWCFServiceClient(CreateBasicHttpBinding(), EndPoint);
        }
        public IList<Event> Events { get; private set; }

        // Binding contract
        private BasicHttpBinding CreateBasicHttpBinding()
        {
            BasicHttpBinding httpBinding = new BasicHttpBinding()
            {
                Name = "basicHttpBinding",
                MaxBufferSize = BindingConstants.ConstMaxBufferSize,
                MaxReceivedMessageSize = BindingConstants.ConstMaxReceivedMessageSize
            };
            TimeSpan timeOut = new TimeSpan(0, 0, 30);

            httpBinding.SendTimeout = timeOut;
            httpBinding.OpenTimeout = timeOut;
            httpBinding.ReceiveTimeout = timeOut;

            return httpBinding;
        }

        public async Task AddEventAsync(Event @event)
        {
            await Task.Run(() => { eventWCFService.AddEvent(ConvertToRemoteEvent(@event)); });
        } 

        public async Task<IList<Event>> GetAllEventsAsync()
        {
            Events = new List<Event>();

            var events = await Task.Run(() => { return eventWCFService.GetAllEvents(); });

            foreach (var item in events)
            {
                Events.Add(ConvertToLocalEvent(item)); 
            }

            return Events;
        }

        private Event ConvertToLocalEvent(ServiceReference1.Event remoteEvent)
        {
            return new Event()
            {
                EventTitle = remoteEvent.EventTitle,
                EventDescription = remoteEvent.EventDescription,
                EventGuid = remoteEvent.EventGuid,
                EventCode = remoteEvent.EventCode,
                Image = remoteEvent.Image,

                Time = remoteEvent.Time,
                Date = remoteEvent.Date,
                Area = remoteEvent.Area,
                Street = remoteEvent.Street,
            };
        }

        private ServiceReference1.Event ConvertToRemoteEvent(Models.Event localEvent)
        {
            return new ServiceReference1.Event()
            {
                EventTitle = localEvent.EventTitle,
                EventDescription = localEvent.EventDescription,
                EventGuid = localEvent.EventGuid,
                EventCode = localEvent.EventCode,
                Image = localEvent.Image,

                Time = localEvent.Time,
                Date = localEvent.Date,
                Area = localEvent.Area,
                Street = localEvent.Street,
            };
        }
    }

Now - stay with me - if you close and reopen the application - and add some events - the data stays (it's all good and working).

But... after around 10-15 minutes - the data on the remote event service gets refreshed completely to its original state of the default 5 events. This means if you create a new event - after 15 minutes - the data gets completely lost. Now - it may not be exactly 15 minutes so let's just say it's around 15-30 minutes. This error is strange - I have no idea as to why this is happening. It could be something to do with Azure - but again - I am not entirely sure.

public class EventOverviewViewModel : ViewModelBase
    {
        private ObservableCollection<Event> _events;
        private ObservableCollection<Event> _eventsSignedUp;

        public ICommand EventSelectedCommand => new Command<Event>(OnEventSelectedCommand);

        // FAB stands = 'floating action button'
        public ObservableCollection<Event> Events
        {
            get => _events;
            set
            {
                _events = value;
                RaisePropertyChanged(nameof(Events));
            }
        }
        public ObservableCollection<Event> EventsSignedUp
        {
            get => _eventsSignedUp;
            set
            {
                _eventsSignedUp = value;
                RaisePropertyChanged(nameof(EventsSignedUp));
            }
        }

        public EventOverviewViewModel(IDialogService dialogService,
                                      IEventService eventService,
                                      IShellNavigationService shellNavigationService,
                                      IThemeService themeService,
                                      ILocalEventDatabase localEventDatabase) : base(dialogService, eventService, shellNavigationService, themeService, localEventDatabase)
        {
            MessagingCenter.Subscribe<Event>(this, MessagingCenterMessages.EVENT_SIGNEDUP, (eventFound) => 
            {
                RaisePropertyChanged(nameof(EventsSignedUp));
            });
        }

        public async Task<EventOverviewViewModel> OnAppearing()
        {
            await LoadData();
            await LoadSQLiteDataToObservableCollection();
            return this;
        }
        private async Task LoadSQLiteDataToObservableCollection()
        {
            try
            {
                var data = await _localEventDatabase.GetRegisteredEventsAsync();

                EventsSignedUp = new ObservableCollection<Event>(data);
            }
            catch (Exception exception)
            {
                _dialogService.ShowAdvancedToast(string.Format($"There was an error loading SQLite: {exception.Message}"), Color.Red, Color.White, TimeSpan.FromSeconds(2));
            }
        }

        private async Task LoadData()
        {
            if (Connectivity.NetworkAccess == NetworkAccess.None)
            {
                _dialogService.ShowAdvancedToast(string.Format("Please turn on your internet to use this app."), Color.Red, Color.White, TimeSpan.FromSeconds(2));
            }
            else
            {
                try
                {
                    var data = await _eventService.GetAllEventsAsync();
                }
                catch (Exception exception)
                {
                    _dialogService.ShowAdvancedToast(string.Format($"There was an error: {exception.Message}"), Color.Red, Color.White, TimeSpan.FromSeconds(2));
                }
            }
        }

        public async void OnEventSelectedCommand(Event @event)
        {
            try
            {
                await _shellNavigationService.NavigateToAsync(nameof(EventDetailView), @event);
            }
            catch (Exception)
            {

            }
        }
    }


On the other hand - my local data service works fine.

I've tried many things - such as resetting the service - redeploying to Azure - and monitoring it. But the bug is still there - I am looking for a solution to this so I can finally finish my application.

This is my first question here so apologies if it's not 100% right :)

Thank you,

EDIT: I am looking for ANY sort of information that may lead me to an ANSWER - any comments are appreciated - I have no idea what the source of the problem is but whoever can help me fix this - I would raise a hat to you!

What I have tried:

Tried to create a singleton instance - reset the WCF service - redeploy to Azure - change ocnfig settings
Posted

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