I'm using aspose.cells to add an image to the background of each page of an excel document to represent a watermark of sorts. The problem I seem to be having is that when I save the document the mime type is not set properly. The code I am using is below:
Workbook workbook = new Workbook();
FileStream watermarkStream = File.OpenRead(filePath);
byte imageData = new byte[watermarkStream.Length];
watermarkStream.Read(imageData, 0, imageData.Length);
for(int i = 0; i < workbook.Worksheets[i].Count; i++)
MemoryStream watermarkedDoc = new MemoryStream();
When I then save the file to my desktop and open with excel it tells me the file is not an excel file. The mimetype appears to be application/octet-stream??