NPOI version 2.2+ MemoryStream.ToArray() 0 bytes

Question

Using NPOI version 2.1.3.1, this line works perfectly, returning a a byte array with data: workbook is an XSSFWorkbook

using (var memoryStream = new MemoryStream())
{
    workbook.Write(memoryStream);
    return  memoryStream.ToArray();
}

when upgrading to 2.2 (and 2.3), this no longer returns any data, the byte array has 0 bytes. no exceptions are thrown, it just silently fails to write data.

Is there a new way to write this workbook out in the updated version?

Answer 1

I don't see any issue in your code. In fact I am using similar approach to get the result. Try type casting your returned value with MemoryStream class or define memorystream variable as type MemoryStream.

Below is my approach

public MemoryStream GetExcelStream()        
 {    
     MemoryStream ms = null;
     using (ms = new MemoryStream())
     {
       workbook.Write(ms); 
     }
   return ms;
 }

MemoryStream excelMS = GetExcelStream();
 ..........................
Response.BinaryWrite(excelMS.ToArray());
Response.End();

If above approach doesn't work, see this link as well NPOI writes 0 bytes in the MemoryStream