Unable to open download save dialog

Question

Using the below code I am unable to show the open/save as file dialog:

        public void ProcessRequest(HttpContext context)
        {
            string link = context.Request.QueryString["Link"];
            string extension = Path.GetExtension(link);
            string fileName = Path.GetFileName(link);
            string fullPath = 
                 String.Format("{0}\\{1}",
                     context.Server.MapPath("~/Content/Uploads/"), 
                     fileName);

            if (File.Exists(fullPath))
            {
                context.Response.ClearContent();
                context.Response.ClearHeaders();
                context.Response.AddHeader(
                    "Content-Length", 
                    new FileInfo(fullPath).Length.ToString());
                string contentType;
                switch (extension)
                {
                    default:
                        contentType = "application/octet-stream";
                        break;
                }
                context.Response.ContentType = contentType;
                context.Response.AddHeader(
                    "Content-Disposition", 
                    String.Format("attachment; filename={0}", fileName));
                context.Response.WriteFile(fullPath, true);
                context.Response.Flush();       
            }
        }

I've tried to close the response, leave the response open, use TrasmitFile(), but I never get any dialog or any feed back whatsoever. I've tried debugging it as well, but no exceptions are being thrown. Tried in IE 7/8, and Chrome. Any help is appreciated.

Thanks!

Below is the Fiddler output:

HTTP/1.1 200 OK Cache-Control: private Content-Length: 3813 Content-Type: application/octet-stream Server: Microsoft-IIS/7.5 Content-Disposition: attachment; filename=b1af9b34-28cc-4479-a056-8c55b41a5ece.txt X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET Date: Thu, 23 Dec 2010 21:51:58 GMT
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What information from Fiddler do you think is important to paste? — O.O, Dec 23 '10 at 21:49
If it makes you feel better, I voted your question _up_ because I'd like to keep track of solving this particular issue in as many scripting languages as possible. ;-) — stealthyninja, Dec 23 '10 at 22:46

score 2 · Answer 1 · edited Apr 09 '12 at 21:28

2

Try changing

contentType = "application/octet-stream";

to

contentType = "application/download";

Update: Try swapping the position of the header and content type

context.Response.AddHeader(
    "Content-Disposition", 
    String.Format("attachment; filename={0}", fileName));
context.Response.ContentType = contentType;
context.Response.AddHeader(
    "Content-Length", 
    new FileInfo(fullPath).Length.ToString());

edited Apr 09 '12 at 21:28

yoozer8

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answered Dec 23 '10 at 22:13

stealthyninja

10,343
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Thanks for the tip. Tried your suggestion, but same result. There are no spaces in the filename as well. – O.O Dec 23 '10 at 22:19
@subt13: I've updated my answer with one last suggestion and then I'm out for now. – stealthyninja Dec 23 '10 at 22:27

score 2 · Accepted Answer · answered Dec 23 '10 at 23:34

Finally figured it out. There is actually no problem with the code I posted. As you can see in the Fiddler output, the contents of the text file were successfully written to the response stream and the headers used were also correct. The actual problem comes from how the actual http request was made. I used a

$.get(urlToGenericHandler);

request using jQuery. The reason why specifically I am not able to download a file using AJAX or a callback model is beyond the scope of this answer. See supported jQuery datatypes here

Anyways, I changed the call from using AJAX to using a basic post-back.

Thanks to all that helped.

Unable to open download save dialog

2 Answers2

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