想实现 按年度 按制品类别 自动编号,代码如下.可编号不正确,请教是那里出错了?

制品编号               入库日期           制品类别

AA☆-2013-001     2013-12-20     AA
BBB-2013-002      2013-12-20     BBB
BBB-2013-002      2013-12-20     BBB
BBB-2013-002      2013-12-20     BBB

出错

\'入库编号
Select e.DataCol.Name
    Case "入库日期","制品类别"
        If e.DataRow.IsNull("入库日期") OrElse e.DataRow.IsNull("制品类别") Then
            e.DataRow("制品编号") = Nothing
        Else
            Dim d As Date = e.DataRow("入库日期")
            Dim y As Integer = d.Year
            Dim fd As Date = New Date(y,1,1) \'
            Dim ld As Date = New Date(y,12,31) \'获得该年的最后一天
            Dim bh As String = Format(e.DataRow("入库日期"),"yyyy") \'取得编号的 位前缀
            Dim qz As String = e.DataRow("制品类别").PadRight(3,"☆") & "-" & bh & "-"
            If e.DataRow("制品编号").StartsWith(qz) = False \'如果编号的前 位不符
                Dim max As String
                Dim idx As Integer
                max = e.DataTable.Compute("Max(制品编号)","入库日期 >= #" & fd & "# And 入库日期 <= #" & ld & "# And [_Identify] <> " & e.DataRow("_Identify")) \'取得该年的最大编号
                If max > "" Then \'如果存在最大编号
                    idx = CInt(max.Substring(10,3)) + 1 \'获得最大编号的后三位顺序号,并加1
                Else
                    idx = 1 \'否则顺序号等于1
                End If
                e.DataRow("制品编号") = qz & Format(idx,"000")
            End If
        End If
End Select

自己顶一下