Converting XLSX file using to a CSV file

Question

I need to convert an XLSX file to another CSV file. I've done a lot of research on how to do this process, but I did not find anything that suited me. I found this Github Gist only Convert an Epplus ExcelPackage to a CSV file

That returns an Array of binary. But apparently it does not work any more.

I'm trying to load Array using LoadFromCollection

FileInfo novoArquivoCSV = new FileInfo(fbd.SelectedPath);
var fileInfoCSV = new FileInfo(novoArquivo + "\\" + nameFile.ToString() + ".csv");

using (var csv = new ExcelPackage(fileInfoCSV))
{
    csv.Workbook.Worksheets.Add(nameFile.ToString());
    var worksheetCSV = csv.Workbook.Worksheets[1];

    worksheetCSV.Cells.LoadFromCollection(xlsx.ConvertToCsv());
}

Answer 1

The code you linked to reads an XLSX sheet and returns the CSV data as a byte buffer through a memory stream.

You can write directly to a file instead, if you remove the memory stream and pass the path to the target file in ConvertToCsv :

public static void ConvertToCsv(this ExcelPackage package, string targetFile)
{
        var worksheet = package.Workbook.Worksheets[1];

        var maxColumnNumber = worksheet.Dimension.End.Column;
        var currentRow = new List<string>(maxColumnNumber);
        var totalRowCount = worksheet.Dimension.End.Row;
        var currentRowNum = 1;

        //No need for a memory buffer, writing directly to a file
        //var memory = new MemoryStream();

        using (var writer = new StreamWriter(targetFile,false, Encoding.UTF8))
        {
        //the rest of the code remains the same
        }

        // No buffer returned
        //return memory.ToArray();
}

Encoding.UTF8 ensures the file will be written as UTF8 with a Byte Order Mark that allows all programs to understand this is a UTF8 file instead of ASCII. Otherwise, a program could read the file as ASCII and choke on the first non-ASCII character encountered.

Answer 2

Checkout the .SaveAs() method in Excel object.

wbWorkbook.SaveAs("c:\yourdesiredFilename.csv", Microsoft.Office.Interop.Excel.XlFileFormat.xlCSV)

Or following:

public static void SaveAs()
{
    Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.ApplicationClass();
    Microsoft.Office.Interop.Excel.Workbook wbWorkbook = app.Workbooks.Add(Type.Missing);
    Microsoft.Office.Interop.Excel.Sheets wsSheet = wbWorkbook.Worksheets;
    Microsoft.Office.Interop.Excel.Worksheet CurSheet = (Microsoft.Office.Interop.Excel.Worksheet)wsSheet[1];

    Microsoft.Office.Interop.Excel.Range thisCell = (Microsoft.Office.Interop.Excel.Range)CurSheet.Cells[1, 1];

    thisCell.Value2 = "This is a test.";

    wbWorkbook.SaveAs(@"c:\one.xls", Microsoft.Office.Interop.Excel.XlFileFormat.xlWorkbookNormal, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlShared, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
    wbWorkbook.SaveAs(@"c:\two.csv", Microsoft.Office.Interop.Excel.XlFileFormat.xlCSVWindows, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlShared, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);

    wbWorkbook.Close(false, "", true);
}

Is there any simple way to convert .xls file to .csv file? (Excel)

There are several other resources online that can help with this ind of thing. Actually, for something generic like this, you should always Google for a solution, and try to figure it out yourself. That's the best way to learn how to do technical things. If you get stuck, or if you have a very specific question, this site is a great place to post your question(s). It seems to me, you probably started here, and you didn't do any preliminary work yourself.