How to restrict the editing of specific cells in WinForms GridGroupingControl?

void hierarchyGrid_QueryCellStyleInfo(object sender, GridTableCellStyleInfoEventArgs e)
{
     //stop user from editing the contents of the grid cell
     e.Style.ReadOnly = (e.TableCellIdentity.TableCellType == GridTableCellType.FilterBarCell)? false : true; 
}

Private Sub hierarchyGrid_QueryCellStyleInfo(ByVal sender As Object, ByVal e As GridTableCellStyleInfoEventArgs)
     'stop user from editing the contents of the grid cell
     e.Style.ReadOnly = If((e.TableCellIdentity.TableCellType = GridTableCellType.FilterBarCell), False, True)
End Sub