public static void ClosedXmlReader(string inFile, string outFile) { var workbook = new ClosedXML.Excel.XLWorkbook(inFile); ClosedXML.Excel.IXLWorksheet sheet = workbook.Worksheets.Worksheet(1); var sb = new StringBuilder(); var rows = sheet.LastRowUsed().RangeAddress.FirstAddress.RowNumber; var columns = sheet.LastColumnUsed().RangeAddress.FirstAddress.ColumnNumber; foreach (var row in sheet.Rows()) { foreach (var cell in row.Cells()) { string s = cell.GetString(); if (s.Contains('\n')) { sb.Append("\"" + s + "\"\t"); } else { sb.Append(s + "\t"); } } sb.Remove(sb.Length - 1, 1); sb.Append("\n"); } File.WriteAllText(outFile, sb.ToString()); }