Programmatically convert Excel 2003 files to 2007+

Question

I'm looking for a way to essentially take a folder of excel files that are the old 2003 file extension .xls and convert them into .xlsm. I realize you can go into the excel sheet yourself and manually do it, but is there anyway to do it with code? Specifically using any sort of library?

Answer 1

This is not my code, but I have used ClosedXML before and it is awesome. I found this on the FAQ asking if it supports Excel 2003 which looks like it should work for you...

To clarify, this uses the Office Interop library not closedXML, but I mentioned it incase you had any additional modifications you needed.

public void Convert(String filesFolder)
{
     files = Directory.GetFiles(filesFolder);

     var app = new Microsoft.Office.Interop.Excel.Application();
     var wb = app.Workbooks.Open(file);
     wb.SaveAs(Filename: file + "x", FileFormat: Microsoft.Office.Interop.Excel.XlFileFormat.xlOpenXMLWorkbook);
     wb.Close();
     app.Quit();
}

Here is the link

hope it helps :D