Asp.net ต้องการให้ข้อมูลใน Footer ของ Gridview Export ออก Excel ด้วย

 Dim core As String
            Dim number As String
            Dim expect As Double
            Dim have As Double
            Dim persen As String
            Dim Sum1 As Double = 0
            Dim chkdate As String = ""
            For i = 0 To GridView1.Rows.Count - 1
                number = CStr(i + 1)
                core = GridView1.Rows(i).Cells(2).Text
                expect = CDbl(GridView1.Rows(i).Cells(3).Text)
                have = CDbl(GridView1.Rows(i).Cells(4).Text)
                persen = GridView1.Rows(i).Cells(5).Text


                .Range("A" & j.ToString()).Value = number + "." + core
                .Range("A" & j.ToString()).HorizontalAlignment = Excel.XlHAlign.xlHAlignLeft

                .Range("G" & j.ToString()).Value = expect
                .Range("G" & j.ToString()).HorizontalAlignment = Excel.XlHAlign.xlHAlignRight

                .Range("H" & j.ToString()).Value = have
                .Range("H" & j.ToString()).HorizontalAlignment = Excel.XlHAlign.xlHAlignRight

                .Range("I" & j.ToString()).Value = persen
                .Range("I" & j.ToString()).HorizontalAlignment = Excel.XlHAlign.xlHAlignRight


                j += 1
            Next