Rename .xml file to .xls

You can read the XML file into a datatable, then use Spire.XLS to convert the datatable to an XLS file.

https://www.nuget.org/packages/Spire.XLS/

using Spire.Xls;
using System.Data;
using System.IO;
using System.Xml;

namespace XmlToExcel
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Create a new Workbook
            Workbook workbook = new Workbook();

            //Get the first worksheet
            Worksheet sheet = workbook.Worksheets[0];

            //Read an xml file into a datatable
            DataTable dt = ReadXmlFile("test.xml");

            //Import data in the datatable into the worksheet
            sheet.InsertDataTable(dt, true, 1, 1);

            //Save the result to an XLS file
            workbook.SaveToFile("XmlToExcel.xls", ExcelVersion.Version97to2003);
        }

        public static DataTable ReadXmlFile(string fileName)
        {
            using (var stream = File.Open(fileName, FileMode.Open, FileAccess.Read))
            {
                using (var reader = XmlReader.Create(stream))
                {
                    var ds = new DataSet();
                    ds.ReadXml(reader);
                    return ds.Tables[0];
                }
            }
        }
    }
}

Hi Naimish

 I have uploaded file . In Datatable it shows 4 fields Author , Last Author Created , Version.

/forums/uploadfile/f61a1a/04132023082802AM/FB leads - Copy.xml

public static DataTable ReadXmlFile(string fileName)
    {
        using (var stream = File.Open(fileName, FileMode.Open, FileAccess.Read))
        {
            using (var reader = System.Xml.XmlReader.Create(stream))
            {
                var ds = new DataSet();
                ds.ReadXml(reader);
                return ds.Tables[0];
            }
        }
    }

Thanks

The "Invalid file signature" error suggests that the file you are trying to read is not in the expected format, or it is corrupted.

One possible reason for this error is that you are trying to open an XML file with an Excel reader. The XML format and Excel format are different, and you cannot simply change the file extension from ".xml" to ".xls" to convert an XML file to an Excel file. Instead, you need to use a library or tool that can convert the XML data to an Excel format.

If you want to read an XML file directly, you can use the XmlReader class instead of the ExcelReader class. Here is an example code snippet that shows how to read an XML file into a DataTable using XmlReader:

public static DataTable ReadXmlFile(string fileName)
{
    using (var stream = File.Open(fileName, FileMode.Open, FileAccess.Read))
    {
        using (var reader = XmlReader.Create(stream))
        {
            var ds = new DataSet();
            ds.ReadXml(reader);
            return ds.Tables[0];
        }
    }
}

Try below code:

string FolderPath = "~/Upload/ExcelUpload/";
string FileNameWithoutExtension = Path.GetFileNameWithoutExtension(FileUpload1.FileName);
string FilePath;

// Check if the uploaded file has an XML extension
if (Path.GetExtension(FileUpload1.FileName).ToLower() == ".xml")
{
    // Save the file with an XLS extension
    FilePath = Server.MapPath(FolderPath + RandomName + FileNameWithoutExtension + ".xls");
}
else
{
    // Save the file with its original extension
    FilePath = Server.MapPath(FolderPath + RandomName + FileUpload1.FileName);
}

FileUpload1.SaveAs(FilePath);

Thanks

Hi AMit

  On thsi code it gives Invalid file signature

                    FileUpload1.SaveAs(FilePath);

UploadSave(Utility.ReadExcelFile(FilePath));

public static DataTable ReadExcelFile(string fileName)
    {
        using (var stream = File.Open(fileName, FileMode.Open, FileAccess.Read))
        {
            // Auto-detect format, supports:
            //  - Binary Excel files (2.0-2003 format; *.xls)
            //  - OpenXml Excel files (2007 format; *.xlsx, *.xlsb)
            using (var reader = ExcelReaderFactory.CreateReader(stream))
            {
                 do
                {
                    while (reader.Read())
                    {
                        // reader.GetDouble(0);
                    }
                } while (reader.NextResult());

                // 2. Use the AsDataSet extension method
                DataSet result = reader.AsDataSet(new ExcelDataSetConfiguration()
                {
                    ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
                    {
                        UseHeaderRow = true
                    }
                });
                return result.Tables[0];
            }
        }
    }

string FolderPath = "~/Upload/ExcelUpload/";
string FilePath = Server.MapPath(FolderPath + RandomName + FileName);

// Check if file extension is .xml
if (Path.GetExtension(FilePath).ToLower() == ".xml")
{
    // Change extension to .xls
    FilePath = Path.ChangeExtension(FilePath, ".xls");
}

FileUpload1.SaveAs(FilePath);