Xamarin.iOS & Eventkit

Question

i have a problem to get an calendar entry from Eventstore via eventfromIdentifier. To Save a Event works fine, but when i tryto retrieve a Event from EventStore, it returns null. I checked other Questions here on stackoverflow and no one fix it. I hope you can help.

Function to save calendar entry, works fine. I get the UUID and save it to the local database.

private void createOneCalendarEntry(VorstellungEventArgs e) {
        EKEvent newEvent = EKEvent.FromStore(CalendarHelper.Current.EventStore);
        newEvent.StartDate = DateHelper.DateTimeToNSDate(e.Vorstellung.Beginn ?? DateTime.Now);
        DateTime StartTime = e.Vorstellung.Beginn ?? DateTime.MinValue;
        var Duration = e.Vorstellung.Dauer ?? 90;
        newEvent.EndDate = DateHelper.DateTimeToNSDate(StartTime.AddMinutes(Duration));
        newEvent.Title = e.Vorstellung.PublikationsTitel;
        newEvent.Notes = e.Vorstellung.ZeitUndOrtString;
        newEvent.Calendar = CalendarHelper.Current.EventStore.DefaultCalendarForNewEvents;

        NSError a;
        try
        {   // Save Note to Calendar to get UUID 
            CalendarHelper.Current.EventStore.SaveEvent(newEvent, EKSpan.ThisEvent, true, out a);
            if (a != null)
            {
                new UIAlertView("Err Saving Event", a.ToString(), null, "ok", null).Show();
                return;
            }
            else
            {   // Test: Show UUID 
                new UIAlertView(newEvent.UUID, "wurden zum Kalendar hinzugefügt", null, "ok", null).Show();
                ViewModel.DataManager.InsertCalID(e.Vorstellung.Id, e.Vorstellung.FilmId, newEvent.UUID);

            }

        }
        catch
        {
            new UIAlertView("Fehler", "Kalendareinträge wurden nicht erstellt", null, "ok", null).Show();
        }

        finally
        {
        }
    }

And here comes the function to call the entry and delete them. "ViewModel.DataManager.getCalID(e.Vorstellung.Id, e.Vorstellung.FilmId)" gives me the UUID that a created upside.

 private void deleteEventfromCalandar(VorstellungEventArgs e)
    {
        NSError a;

        // Get UUID from local Database an get Event from UUID THIS RETURNS ALWAYS NULL 
        EKEvent EventToDelete = CalendarHelper.Current.EventStore.EventFromIdentifier(ViewModel.DataManager.getCalID(e.Vorstellung.Id, e.Vorstellung.FilmId));

        // Delete current event from calendar
        CalendarHelper.Current.EventStore.RemoveEvent(EventToDelete, EKSpan.ThisEvent,true, out a);
        new UIAlertView("Erfolg", "Kalendareintrag mit "+EventToDelete.UUID+" wurde gelöscht", null, "ok", null).Show();
    }

Here the Eventstore, copied from Xamarin doku

class CalendarHelper
{
    public static CalendarHelper Current
    {
        get { return current; }
    }
    private static CalendarHelper current;

    public EKEventStore EventStore
    {
        get { return eventStore; }
    }
    protected EKEventStore eventStore;

    static CalendarHelper()
    {
        current = new CalendarHelper();
    }
    protected CalendarHelper()
    {
        eventStore = new EKEventStore();
    }

}

And Yes my App have permission to calendar

CalendarHelper.Current.EventStore.RequestAccess(EKEntityType.Event,
            (bool granted, NSError e) =>
            {
                if (granted)
                {

                }
                else
                {
                    new UIAlertView("Access Denied", "user Denied Access to Calendar Data", null, "ok", null).Show();
                }
            });

Answer 1

I fixed it! The Problem was that i saved the wrong identifier. There are two different identifier,"UUID" and "Eventidentifier". With the Eventidentifier my code just works fine.

 ViewModel.DataManager.InsertCalID(e.Vorstellung.Id, e.Vorstellung.FilmId, newEvent.Eventidentifier);

and

new UIAlertView("Erfolg", "Kalendareintrag mit "+EventToDelete.Eventidentifier +" wurde gelöscht", null, "ok", null).Show();
}