How can change the DataConverter?

i think is right

public class CustomerGridBuilder : DevExGridBuilderBase {

      /// <summary>Recipe for building the Grid.</summary>
      protected override void BuildCore() {
        StyleGridToStandard();
        EntityPropertyDescriptors.CustomerPropertyDescriptor descriptors = EntityPropertyDescriptors.Customer;
        AddColumnReadOnly(descriptors.Id, "Id");

        IEntityEditorController editor = EditorService.GetEditor(WorkItem.ID);
        list = ((Customer)editor.RootEntity).Orders;
        list.ListChanged += new System.ComponentModel.ListChangedEventHandler(list_ListChanged);
        cbd = AddColumn(descriptors.ContactName, "Name");
        if (list.Count > 0)
            cbd.DataConverter = IdeaBlade.UI.TextConverter.ReadOnlyField;
        else
            cbd.DataConverter = IdeaBlade.UI.TextConverter.OptionalField;
     }

      void list_ListChanged(object sender, System.ComponentModel.ListChangedEventArgs e)
      {
          if (e.ListChangedType == System.ComponentModel.ListChangedType.ItemAdded ||
              e.ListChangedType == System.ComponentModel.ListChangedType.ItemDeleted)
          {

              if (list.Count > 0)
                  cbd.DataConverter = IdeaBlade.UI.TextConverter.ReadOnlyField;
              else
                  cbd.DataConverter = IdeaBlade.UI.TextConverter.OptionalField;
          }
      }
   
    /// <summary>Get the grid column widths.</summary>
    protected IEntityEditorService EditorService {
      get {
        if (mEditorService == null) {
          mEditorService = WorkItem.Services.Get<IEntityEditorService>();
        }
        return mEditorService;
      }
    }

      private ControlBindingDescriptor cbd;
      private ReadOnlyEntityList<SizesPalletLn> list;
      private IEntityEditorService mEditorService;