I’m using CsvHelper.Excel.ExcelWriter class from Nuget Pack (CsvHelper.Excel.Core).

It works if I only try to write on FileStream, but it doens’t on MemoryStream.

It Works

 using (var w = new CsvHelper.Excel.ExcelWriter("C:\temp\test.xlsx", CultureInfo.InvariantCulture))
 {
     await w.WriteRecordsAsync<MyItem>(items);
     w.Dispose();
 }

It doesn’t work

 var mm = new MemoryStream();
 var w = new CsvHelper.Excel.ExcelWriter(mm, CultureInfo.InvariantCulture, true);
 await w.WriteRecordsAsync<MyItem>(items);
 mm.Flush();
 w.Dispose();

Any suggestions?