ASP.NET MVC FileStreamResult, fileDownloadName is not used

Question

The following returns a PDF which the browser tries to directly display inline. This works correctly. However, if I try to download the file, the download name is not "myPDF.pdf", but instead the ID in the route (myapp/controller/PDFGenerator/ID). Is it possible to set the file download name to be "myPDF.pdf"?

public FileStreamResult PDFGenerator(int id)
{
    MemoryStream ms = GeneratePDF(id);

    byte[] file = ms.ToArray();
    MemoryStream output = new MemoryStream();
    output.Write(file, 0, file.Length);
    output.Position = 0;
    HttpContext.Response.AddHeader("content-disposition", 
    "inline; filename=myPDF.pdf");

    return File(output, "application/pdf", fileDownloadName="myPDF.pdf");
}

Answer 1

No, this is not possible with a PDF displayed inline. You could achieve this if you send the Content-Disposition header with as an attachment:

public ActionResult PDFGenerator(int id)
{
    Stream stream = GeneratePDF(id);
    return File(stream, "application/pdf", "myPDF.pdf");
}

Also notice how I removed the unnecessary MemoryStream you were using and loading the PDF in memory where you could have directly streamed it to the client which would have been far more efficient.

Answer 2

If you are using FileStreamResult to download the file, try using this in controller

Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", "attachment; filename=FileName.pdf");