private async void DoDeleteMedicalPractice() { var dialog = new UserDialogBox("", $"Praxis [{SelectedMedicalPractice.Name}] wirklich löschen?", MessageBoxButton.OKCancel); var result = await dialog.ShowMahAppsDialog(); if (result == MessageDialogResult.Affirmative) { var practiceToDelete = SelectedMedicalPracticeObject; dataCenter.RemoveMedicalPractice(practiceToDelete); MedicalPractices.Remove(SelectedMedicalPractice); foreach (var user in dataCenter.GetAllUsers()) { if (user.ListOfAccessableMedicalPractices.Contains(practiceToDelete.Id)) { var updatedUser = user.UpdateListOfAccessableMedicalPractices( user.ListOfAccessableMedicalPractices.Where(medPracId => medPracId != practiceToDelete.Id) .ToList() ); dataCenter.UpdateUser(updatedUser); } } SelectedMedicalPractice = null; } }