private void GroupByComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) { ImpBL bl = ImpBL.Instance; try { if (groupByComboBox.SelectedIndex == 0) { groupingDataGrid.Items.Clear(); groupingDataGrid.CanUserReorderColumns = false; groupingDataGrid.CanUserResizeColumns = false; groupingDataGrid.CanUserResizeRows = false; groupingDataGrid.CanUserSortColumns = false; var o = bl.GroupOrdersByStatus(); foreach (var item in o) { foreach (var order in item) { groupingDataGrid.Items.Add(order); } groupingDataGrid.Items.Add(0); } } if (groupByComboBox.SelectedIndex == 1) { groupingDataGrid.Items.Clear(); groupingDataGrid.CanUserReorderColumns = false; groupingDataGrid.CanUserResizeColumns = false; groupingDataGrid.CanUserResizeRows = false; groupingDataGrid.CanUserSortColumns = false; var o = bl.GroupOrdersByHostingUnit(); foreach (var item in o) { foreach (var order in item) { groupingDataGrid.Items.Add(order); } groupingDataGrid.Items.Add(0); } } } catch (Exception ex) { MessageBox.Show(ex.Message); } }