public async void OnNavigatedTo(NavigationContext navigationContext) { _regionNavigationService = navigationContext.NavigationService; Student = (StudentViewModel)navigationContext.Parameters[NavigationParameterKeys.Student]; if (Student != null) { var vaccinations = await Student.GetVaccinationAsync(); var sortedVaccinations = vaccinations.OrderByDescending(x => x.Date).ToList(); _vaccinations.Clear(); _vaccinations.AddRange(sortedVaccinations); var diseaseGroup = await Student.GetDiseaseGroupAsync(); _diseaseGroup.Clear(); _diseaseGroup.AddRange(diseaseGroup); } }