在MVC 4中返回下载在Android上不起作用

Question

I'm a first time poster so please excuse my ignorance on posting technique. I have been searching for hours and cannot seem to find the answer to this so hopefully the smarter people in the room can help? I have a web application written in .net MVC 4 that connects to several cloud service APIs. The user can then download files from this web app. I've been able to get this to work on all platforms except android. When I try to download the file on Android it hangs and eventually fails. While downloading it has the filename but says <unknown>. Does anyone have a solution for this? Here is the code I'm using:

if (String.IsNullOrEmpty(type))
{
    type = "application/octet-stream";
}

byte[] file = openDropBoxFile(path, filename);

if (file != null)
{                    
    return File(file, type, filename);
}

Thanks Slack Shot, sadly it didn't change the behavior on android. Here's how I changed the code in case I implemented your solution incorrectly:

if (String.IsNullOrEmpty(type))
{
    type = "application/octet-stream";
}        

byte[] file = openDropBoxFile(path, filename);
if (file != null)
{
    var cd = new System.Net.Mime.ContentDisposition
    {
        FileName = filename,
        Inline = false,
    };
    Response.AppendHeader("Content-Disposition", cd.ToString());
    return File(file, type);
}

Some more information on the issue. I was able to get the download to work on Firefox for android, but not the native browser or Google Chrome for Android.

Headers as reported by my last attempt, (I also tried without Length and used chunked transfer encoding instead):

HTTP/1.1 200 OK
Cache-Control: private
Content-Length: 45113
Content-Type: application/pdf
Server: Microsoft-IIS/8.0
Content-Disposition: attachment; filename="testfile.pdf"
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Sat, 09 Nov 2013 17:55:40 GMT

UPDATE: We've solved part of the issue!!

Turns out if we turn off our SSL the downloads work just fine. Anyone run into this?

Answer 1

You might want to try adding a Content-Disposition Header.

       var cd = new System.Net.Mime.ContentDisposition
        {
                // for example foo.bak
                FileName = "Summary.csv",

                // always prompt the user for downloading, set to true if you want 
                // the browser to try to show the file inline
                Inline = false,
        };
        Response.AppendHeader("Content-Disposition", cd.ToString());
        return File(model.SummaryDownload.Content().ToArray(), "text/csv");