How to get file from FileStremResult object in Asp.Net MVC Web application?

Question

I have Asp.Net MVC Web application with form. When I submit form app runs method:

[HttpPost]
public ActionResult MyMethod(MyViewModel model)
{
    FileStreamResult document = CreateDocument(model);
    return document;
}

And browser opens generated file (PDF) in the same tab. I'm doesn't want to open this file, instead I want to download it to disk. How to implement this action?

Slicksim · Accepted Answer · 2015-10-30T08:46:33.433

3

You will need to tell the browser that it is a download, rather than a file.

You can do this by setting 2 headers (content type and content disposition), and then writing your PDF to the response stream.

[HttpPost]
public ActionResult MyMethod(MyViewModel model)
{

     HttpResponseBase response = ControllerContext.HttpContext.Response;

    response.ContentType = "application/pdf";
    response.AppendHeader("Content-Disposition", "attachment;filename=yourpdf.pdf");

    FileStreamResult document = CreateDocument(model);
    //Write you document to response.OutputStream here
    document.FileStream.Seek(0, SeekOrigin.Begin);
    document.FileStream.CopyTo(response.OutputStream, document.FileStream.Length);

    response.Flush();

    return new EmptyResult();
}

edited Oct 30 '15 at 08:46

answered Oct 30 '15 at 08:27

Slicksim

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How to write document to response.OutputStream (OutputStream doesn't have setter)? I have third party library that returns only FileStreamResult object. – Oblomingo Oct 30 '15 at 08:41
I've updated it with some pseudo code, you might need to tweak it a bit – Slicksim Oct 30 '15 at 08:46
Thank a lot, now it works perfectly! Actually, we even doesn't need to write OutStream, enough to change ContentType and AppendHeader! – Oblomingo Oct 30 '15 at 08:59
Is it possible to implement loading spinner in form. Show spinner on submit (easy to do) and hide on getting file (how to get event?). – Oblomingo Oct 30 '15 at 09:06

score 0 · Answer 2 · answered Oct 30 '15 at 08:26

You should return a FileStreamResult (this will force a download together with the "FileDownloadName". By specifying an ActionResult as a method return value you have the flexibility of returning other stuff as well (HttpStatusCodes, View()'s, or Content()'s).

public ActionResult DownloadSomeFile()
    {
        using (var ms = new MemoryStream())
        {
            var response = GetMyPdfAsStream(); // implement this yourself
            if (response is StreamContent)
            {
                var responseContent = response as StreamContent;
                await responseContent.CopyToAsync(ms);
                byte[] file = ms.ToArray();
                MemoryStream output = new MemoryStream();
                output.Write(file, 0, file.Length);
                output.Position = 0;

                return new FileStreamResult(output, "application/pdf") { FileDownloadName = fileName };
            }
            else
            {
                return Content("Something went wrong: " + response.ReasonPhrase);
            }
            return null;
        }

    }

How to "implement this"? How to convert FileStreamResult to StreamContent? — Oblomingo, Oct 30 '15 at 08:43
This stackoverflow answer shows you how to read a file into a memory stream directly. [http://stackoverflow.com/a/8624188/1430141](http://stackoverflow.com/a/8624188/1430141) — Erik J., Oct 30 '15 at 11:31

How to get file from FileStremResult object in Asp.Net MVC Web application?

2 Answers2