VirtualStringTree 单元格刷新问题？

OnGetText(Sender: TBaseVirtualTree;
  Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;
  var CellText: WideString);
var
  p_Data:pData;
begin
  p_Data := t_DataList.Items[Node.index];
  case Column of
   0 : CellText := inttostr(node.Index+1);
   1 : CellText := p_Data.caption;
  end;
end;现在我改变了 p_Data.caption,怎么更新VirtualStringTree中我修改的那个单元格(注：请不要用Repaint)？