cxGrid Master/Detail主从视图，如何获得从表的数据

var  
  AMasterView, ADetailView: TcxGridDBTableView;  
  ADetailDataController: TcxCustomDataController;  
begin  
  AMasterView := GridFilesVw;  
  ADetailDataController := AMasterView.DataController.GetDetailDataController(AMasterView.DataController.FocusedRecordIndex,0);  
  ADetailView := TcxGridDBDataController(ADetailDataController).GridView as TcxGridDBTableView;  
  //Caption := IntToStr(ADetailView.DataController.RecordCount);  
  ShowMessage(ADetailView.DataController.Values[ADetailView.DataController.FocusedRecordIndex, ADetailView.GetColumnByFieldName('id').Index]);