Dim doc As New PrintDoc \'定义一个新报表
Dim rt As New prt.RenderTable \'定义一个新表格
Dim tb as Table = Tables("订单")
Dim ColNames As New List(Of String)
For Each cl As Col In tb.Cols \'排除隐藏列
    If cl.Visible Then
        ColNames.Add(cl.Name)
    End If
Next
rt.Width = "Auto" \'表格宽度为自动,也就是等于各列设置宽度之和
rt.SplitHorzBehavior = prt.SplitBehaviorEnum.SplitIfNeeded \'表格宽度超出页宽时，可以水平换页
rt.Style.Font = tb.Font
For c As Integer = 0 To ColNames.Count - 1 \'逐列设置和填入内容
    rt.Cells(0,c).Text = ColNames(c) \'列名作为标题
    rt.Cells(0,c).Style.TextAlignHorz = prt.AlignHorzEnum.Center \'标题内容水平居中
    rt.Cols(c).Width = tb.Cols(ColNames(c)).PrintWidth \'列宽等于实际列宽
    If tb.Cols(ColNames(c)).IsNumeric Orelse tb.Cols(ColNames(c)).IsDate Then \'如果是数值或日期列
        rt.Cols(c).Style.TextAlignHorz = prt.AlignHorzEnum.Right \'数据水平靠右
    End If
    For r As integer = 0 To tb.Rows.Count -1 \'开始填入该列内容
        rt.Cells(r + 1, c).Text = tb.Rows(r)(ColNames(c))
    Next
Next
rt.Style.Gridlines.All = New prt.Linedef(Color.Gray) \'灰色网格线
rt.CellStyle.Spacing.All = 0.5 \'单元格内距设为0.5毫米
rt.Rows(0).Style.TextAlignHorz = prt.AlignHorzEnum.Center \'第一行内容水平居中
rt.RowGroups(0,1).Header = prt.TableHeaderEnum.All \'利用行组,将第一行设为表头.
doc.Body.Children.Add(rt) \'将表格加入到报表
doc.Preview()

求这个代码生成的报表后,能在这个报表的最后增加一"总计"行,对订单表的"数量"和"金额"列累计,折扣列为平均   的代码  .

谢谢!