I have an \"excel library\" workbook and want to convert it to a byte[] so I could return the data with the File method exist in asp.net mvc controller.
There are \"Save\" a
Do you need to convert it to a byte[]? File can also return a stream.
Workbook workbook = new Workbook();
Worksheet worksheet = new Worksheet("First Sheet");
worksheet.Cells[0, 1] = new Cell(9999999);
workbook.Worksheets.Add(worksheet);
MemoryStream m = new MemoryStream();
workbook.SaveToStream(m);
return File(m, "application/vnd.ms-excel");
If you have a SaveToStream you could pass in a MemoryStream into that method. Then, once all the bytes are written call ToArray() on the memory stream, which should give you a byte array.