' Method that returns xml node from excel file.
Private Shared Function GetTableNodeFromExcelFile(ByVal fileName As String) As XmlNode
  Dim ef As New ExcelFile
  Dim options As New HtmlExporterOptions

  ef.LoadXlsx(fileName, XlsxOptions.None)

  ' By default grid lines are showed.
  options.ShowGridLines = False

  ' Overrides default MethodRowToHtml by assigning CustomRowToHtml to it.
  ' Default MethodRowToHtml is DefaultHtmlExporter.DefaultRowToHtml.
  ' Any method in exporting process can be overridden this way.
  options.MethodRowToHtml = New RowToHtmlDelegate(AddressOf Program.CustomRowToHtml)

  ' Range that is exporting is set to used range of the first worksheet.
  Dim range As CellRange = ef.Worksheets.Item(0).GetUsedCellRange

  Return DefaultHtmlExporter.DefaultTableToHtml(options, range)
End Function

' Method that exports every row as default one, but for pair rows sets font style to bold.
Private Shared Function CustomRowToHtml(ByVal options As HtmlExporterOptions, ByVal row As ExcelRow, ByVal range As CellRange, ByVal htmlRowIndex As Integer) As XmlNode
  ' Default method can be called from anywhere, including methods that are overriding default ones.
  Dim rowNode As XmlNode = DefaultHtmlExporter.DefaultRowToHtml(options, row, range, htmlRowIndex)

  If ((htmlRowIndex Mod 2) = 0) Then
    Dim styleAttribute As XmlAttribute = rowNode.Attributes.ItemOf("style")

    ' If style attribute don't exist, new style attribute is created.
    If (styleAttribute Is Nothing) Then
      styleAttribute = options.ExportingXmlDocument.CreateAttribute("style")
      rowNode.Attributes.Append(styleAttribute)
    End If

    ' Sets font-weight to bold.
    styleAttribute.Value = (styleAttribute.Value & "font-weight:700;")
  End If

  Return rowNode
End Function

// Method that returns xml node from excel file.
private static XmlNode GetTableNodeFromExcelFile(string fileName)
{
  ExcelFile ef = new ExcelFile();
  HtmlExporterOptions options = new HtmlExporterOptions();

  ef.LoadXlsx(fileName, XlsxOptions.None);

  // By default grid lines are showed.
  options.ShowGridLines = false;

  // Overrides default MethodRowToHtml by assigning CustomRowToHtml to it.
  // Default MethodRowToHtml is DefaultHtmlExporter.DefaultRowToHtml.
  // Any method in exporting process can be overridden this way.
  options.MethodRowToHtml = CustomRowToHtml;

  // Range that is exporting is set to used range of the first worksheet.
  CellRange range = ef.Worksheets[0].GetUsedCellRange();

  return DefaultHtmlExporter.DefaultTableToHtml(options, range);
}

// Method that exports every row as default one, but for pair rows sets font style to bold.
private static XmlNode CustomRowToHtml(HtmlExporterOptions options, ExcelRow row, CellRange range, int htmlRowIndex)
{
  // Default method can be called from anywhere, including methods that are overriding default ones.
  XmlNode rowNode = DefaultHtmlExporter.DefaultRowToHtml(options, row, range, htmlRowIndex);

  if (htmlRowIndex % 2 == 0)
  {
    XmlAttribute styleAttribute = rowNode.Attributes["style"];

    // If style attribute don't exist, new style attribute is created.
    if (styleAttribute == null)
    {
      styleAttribute = options.ExportingXmlDocument.CreateAttribute("style");
      rowNode.Attributes.Append(styleAttribute);
    }

    // Sets font-weight to bold.
    styleAttribute.Value += "font-weight:700;";
  }

  return rowNode;
}