ASP C# Send File to Client

Question

Trying to send a file to the browser for download but after fiddling with it for over an hour can't seem to get it to work correctly.

I'm using the following code

    string filePath = Server.MapPath("/exports/test.txt");
    string downloadedFileName = "test.txt";

    Response.ContentType = "text/plain";
    Response.AppendHeader("content-disposition", "attachment; filename=" + downloadedFileName);
    Response.TransmitFile(filePath);
    Response.End();

It downloads to the browser but the file is filled with HTML from the page instead of the contents of the file. If I write out the directory of server.MapPath the file is located in that directory.

I'm eventually going to use this to send a accdb or mdb database to the browser, I'm just using txt as it's easy to find a proof of concept example online. What would I need to change outside of the ContentType if anything. Also would should the ContentType be for a database?

Thanks for any help in advance!

possible duplicate of Response.WriteFile

Agat
– Agat

2013-11-04 23:13:27 +00:00
Commented Nov 4, 2013 at 23:13 — Agat
– Agat, Commented Nov 4, 2013 at 23:13

Community · Accepted Answer · 2017-05-23 10:31:20Z

3

It's probably because there is already some output queued in the Response stream ready for transmit. You must first clear it before transmitting your file. If you're using ASP.NET web forms, this will break your page though as the postback behavior will no longer work.

See related SO question and answer.

edited May 23, 2017 at 10:31

CommunityBot

11 silver badge

answered Nov 4, 2013 at 23:08

Erik Noren

4,3391 gold badge27 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Agat · Accepted Answer · 2013-11-04 23:11:30Z

3

This is how it usually works for me:

Response.Clear();

if (Request.Browser != null && Request.Browser.Browser == "IE")
    sFileName = HttpUtility.UrlPathEncode(sFileName);

// Response.Cache.SetCacheability(HttpCacheability.Public); // that's upon you

Response.AddHeader("Content-Disposition", "attachment;filename=\"" + sFileName + "\"");
                                                            // ^                   ^
// Response.AddHeader("Content-Length", new FileInfo(sFilePath).Length.ToString()); // upon you 
Response.WriteFile(sFilePath);

Response.Flush();
Response.End();

answered Nov 4, 2013 at 23:11

Agat

4,8593 gold badges38 silver badges68 bronze badges

Comments

Migol · Accepted Answer · 2013-11-04 23:10:56Z

0

Try using .ashx generic handler to send file to browser bypassing most of the ASP.NET stack.

answered Nov 4, 2013 at 23:10

Migol

8,4879 gold badges49 silver badges69 bronze badges

Collectives™ on Stack Overflow

ASP C# Send File to Client

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related