private async void Grid_KeyDown(object sender, KeyEventArgs e) { if (e.Key == Key.Back) { if (PreviousDiagnosesGrid.SelectedItem is Diagnosis diagnosis) { if (await HttpHandler.DeleteDiagnosis(diagnosis)) { _patient.Diagnoses.Remove(diagnosis); PreviousDiagnosesGrid.Items.Remove(PreviousDiagnosesGrid.SelectedItem); PreviousDiagnosesGrid.Items.Refresh(); } } else { MessageBox.Show("Please select a diagnosis", "Delete failed", MessageBoxButton.OK, MessageBoxImage.Warning); } } }