CSV encoding issues (Microsoft Excel)

Question

I am dynamically creating CSV files using C#, and I am encountering some strange encoding issues. I currently use the ASCII encoding, which works fine in Excel 2010, which I

Answer 1

I'm using Windows ANSI codepage 1252 without any problems on Excel 2003. I explicitly changed to this because of the same issue you are seeing.

private const int WIN_1252_CP = 1252; // Windows ANSI codepage 1252

this._writer = new StreamWriter(fileName, false, Encoding.GetEncoding(WIN_1252_CP));

Answer 2

I've successfully used UTF8 encoding when writing CSV files intended to work with Excel.

The only problem I had was making sure to use the overload of the StreamWriter constructor that takes an encoding as a parameter. The default encoding of StreamWriter says it is UTF8 but it's really UTF8-Without-A-Byte-Order-Mark and without a BOM Excel will mess up characters using multiple bytes.

Answer 3

You need to add Preamble to file:

        var data = Encoding.UTF8.GetBytes(csv);
        var result = Encoding.UTF8.GetPreamble().Concat(data).ToArray();
        return File(new MemoryStream(result), "application/octet-stream", "file.csv");