主题：二维码

下面批量形成二维码的代码，怎么改成只生成选定行的二维码？

Dim  doc As  New   PrintDoc
 Dim  rg As  prt.RenderGraphics
 Dim  Bar As  New   BarCodeBuilder
 Bar.Symbology =   Barpro.Symbology.QRCode
 Doc.Stacking =  prt.StackingRulesEnum.InlineLeftToRight
 For Each  r As  Row In Tables("档案").Rows
      bar.Code =  r ("编号") & "," & r("作者") & "," & r("制作日期") & "," & r("说明")  & ","
      rg =  new  prt.RenderGraphics
      bar.DrawOnCanvas(rg.Graphics,0,0,1)
      rg.Style.Spacing.All =  3
      Doc.Body.Children.Add(rg)
 Next
 Doc.Preview()