public async void OnNavigatedTo(NavigationParameters parameters) { // check for UpdateEvent with event id to update in calendar var data = parameters.Where(x => x.Key == "UpdateEvent").FirstOrDefault(); if (data.Value != null) { var eventid = data.Value.ToString(); var currentevent = EventsCollection.Where(x => x.Notes == eventid).FirstOrDefault(); if (currentevent == null) { return; } ApiServiceIndividual api = new ApiServiceIndividual(); var singleEvent = await api.GetEventSingleAsync(eventid); if (singleEvent == null) { return; } currentevent.Subject = singleEvent.TitleInfo; } }