VB.Net อ่านข้อมูลจาก DataGridVIewเขียนใน XML เขียนได้แล้วแต่ถ้ามีการเขียนต่อ จากทำให้ error เนื่องจาก มี node เกิดมา

  Private Sub generateXML()
        'On Error Resume Next
        Dim j As Integer = 0
        Dim writerXML As XmlTextWriter
        'Dim dtRow As DataRow

        If IO.File.Exists(".\XMLFileBreakBill.xml") Then
            ds = New DataSet
            ds.ReadXml(".\XMLFileBreakBill.xml")

            If ds.Tables.Count = 0 Then
                writerXML = New XmlTextWriter(".\XMLFileBreakBill.xml", System.Text.Encoding.UTF8)
                writerXML.WriteStartDocument(True)
                writerXML.Formatting = Formatting.Indented
                writerXML.Indentation = 4
                writerXML.WriteStartElement("breakBill")

                writerXML.WriteStartElement("listFollowBill")

                writerXML.WriteStartElement("Id")
                writerXML.WriteString("1")
                writerXML.WriteEndElement()

                For j = 0 To dgviewSell.Rows.Count - 1
                    writerXML.WriteStartElement("List")

                    writerXML.WriteStartElement("product_name")
                    writerXML.WriteString(dgviewSell.Rows.Item(j).Cells(0).Value.ToString)
                    writerXML.WriteEndElement()

                    writerXML.WriteStartElement("sell_price")
                    writerXML.WriteString(dgviewSell.Rows.Item(j).Cells(1).Value.ToString)
                    writerXML.WriteEndElement()

                    writerXML.WriteStartElement("quantity")
                    writerXML.WriteString(dgviewSell.Rows.Item(j).Cells(2).Value.ToString)
                    writerXML.WriteEndElement()

                    writerXML.WriteStartElement("pay")
                    writerXML.WriteString(dgviewSell.Rows.Item(j).Cells(3).Value.ToString)
                    writerXML.WriteEndElement()

                    writerXML.WriteStartElement("sum_price")
                    writerXML.WriteString(dgviewSell.Rows.Item(j).Cells(4).Value.ToString)
                    writerXML.WriteEndElement()

                    writerXML.WriteEndElement()
                Next

                writerXML.WriteEndElement()
                writerXML.WriteEndElement()
                writerXML.WriteEndDocument()
                writerXML.Close()
            Else
                '    For j = 0 To dgviewSell.Rows.Count - 1
                '        ds.Tables(0).Rows.Add(ds.Tables(0).NewRow())
                '        ds.Tables(0).Rows(ds.Tables(0).Rows.Count - 1)("product_name") = dgviewSell.Rows.Item(j).Cells(0).Value.ToString
                '        ds.Tables(0).Rows(ds.Tables(0).Rows.Count - 1)("sell_price") = dgviewSell.Rows.Item(j).Cells(1).Value.ToString
                '        ds.Tables(0).Rows(ds.Tables(0).Rows.Count - 1)("quantity") = dgviewSell.Rows.Item(j).Cells(2).Value.ToString
                '        ds.Tables(0).Rows(ds.Tables(0).Rows.Count - 1)("pay") = dgviewSell.Rows.Item(j).Cells(3).Value.ToString
                '        ds.Tables(0).Rows(ds.Tables(0).Rows.Count - 1)("sum_price") = dgviewSell.Rows.Item(j).Cells(4).Value.ToString
                '    Next
                '    ds.AcceptChanges()
                '    ds.WriteXml(".\XMLFileBreakBill.xml")
            End If
        Else
            Console.WriteLine(" Error : sub generate xml is not file xml")
            Exit Sub
        End If
    End Sub