主题：专业报表-分组打印(按月分组)

Dim doc As New PrintDoc
Dim rt As Prt.RenderTable
Dim rx As prt.RenderText
Dim tbl As Table = Tables("客户")
Dim Rows As List(Of DataRow)
Dim Regions As List(Of String) = tbl.DataTable.GetValues("地区")
doc.Pagesetting.LandScape = True
For Each Region As String In Regions
    rx = New prt.RenderText
    rx.Style.FontSize = 14
    rx.Style.FontBold = True
    rx.Style.Spacing.Bottom = 2
    rx.Text = "地区: " & Region
    doc.Body.Children.Add(rx)
    rt = New prt.RenderTable
    rt.Style.Font = Tables("客户").Font
    rt.Style.TextAlignVert = prt.AlignVertEnum.Center
    rt.Style.GridLines.All = New prt.LineDef(0.3,Color.LightGray)
    rt.Style.Spacing.Bottom = 5
    rt.CellStyle.Spacing.All = 1
    rt.Style.Font = tbl.Font
    Rows = tbl.Datatable.Select("[地区] = '" & Region & "'")
    For c As integer = 0 To tbl.Cols.Count - 1
        rt.Cells(0,c).Text = tbl.Cols(c).Name
        rt.Cols(c).Width = tbl.Cols(c).PrintWidth
        For r As integer = 0 To Rows.Count -1
            rt.Cells(r + 1, c).Text = rows(r)(tbl.Cols(c).Name)
        Next
    Next
    rt.RowGroups(0,1).Header = prt.TableHeaderEnum.All
    doc.Body.Children.Add(rt)
Next
doc.preview()

如果要按日期中的"月"分组的话,怎么获得日期中不重复的"月"?又怎么按照不同月份生成报表?