Convert XLSM to XLSX

Question

I\'m using the EPPLUS library to read data from Excel to create another file. Unfortunately it does not support the .XLSM extension file. Is there a nice way to convert .X

Answer 1

Using the Open XML SDK, like in amurra's answer, but in addition to changing doc type, VbaDataPart and VbaProjectPart should be removed, otherwise Excel will show error a file is corrupted.

using (var inputStream = File.OpenRead("C:\\temp\\test.xlsm"))
using (var outStream = new MemoryStream()) {
    inputStream.CopyTo(outStream);
    using (var doc = SpreadsheetDocument.Open(outStream, true)) {
        doc.DeletePartsRecursivelyOfType<VbaDataPart>();
        doc.DeletePartsRecursivelyOfType<VbaProjectPart>();
        doc.ChangeDocumentType(DocumentFormat.OpenXml.SpreadsheetDocumentType.Workbook);
    }
    File.WriteAllBytes("C:\\temp\\test.xlsx", outStream.ToArray());
}

Answer 2

In order to do this you will need to use the Open XML SDK 2.0. Below is a snippet of code that worked for me when I tried it:

byte[] byteArray = File.ReadAllBytes("C:\\temp\\test.xlsm");
using (MemoryStream stream = new MemoryStream())
{
    stream.Write(byteArray, 0, (int)byteArray.Length);
    using (SpreadsheetDocument spreadsheetDoc = SpreadsheetDocument.Open(stream, true))
    {
       // Change from template type to workbook type
       spreadsheetDoc.ChangeDocumentType(SpreadsheetDocumentType.Workbook);
    }
    File.WriteAllBytes("C:\\temp\\test.xlsx", stream.ToArray()); 
}

What this code does is it takes your macro enabled workbook file and opens it into a SpreadsheetDocument object. The type of this object is MacroEnabledWorkbook, but since you want it as a Workbook you call the ChangeDocumentType method to change it from a MacroEnabledWorkbook to a Workbook. This will work since the underlying XML is the same between a .xlsm and a .xlsx file.