ASP.NET MVC download image rather than display in browser

Question

Rather than displaying a PNG in the browser window, I'd like the action result to trigger the file download dialogue box (you know the open, save as, etc). I can get this to work with the code below using an unknown content type, but the user then has to type in .png at the end of the file name. How can I accomplish this behavior without forcing the user to type in the file extension?

    public ActionResult DownloadAdTemplate(string pathCode)
    {
        var imgPath = Server.MapPath(service.GetTemplatePath(pathCode));
        return base.File(imgPath, "application/unknown");
    }

Solution....

    public ActionResult DownloadAdTemplate(string pathCode)
    {
        var imgPath = Server.MapPath(service.GetTemplatePath(pathCode));
        Response.AddHeader("Content-Disposition", "attachment;filename=DealerAdTemplate.png");
        Response.WriteFile(imgPath);
        Response.End();
        return null;
    }

Solution 1

I believe you can control this with the content-disposition header.

Response.AddHeader(
       "Content-Disposition", "attachment; filename=\"filenamehere.png\""); 

Solution 2

You need to set the following headers on the response:

• Content-Disposition: attachment; filename="myfile.png"
• Content-Type: application/force-download

Solution 3

I actually came here because I was looking for the opposite effect.

    public ActionResult ViewFile()
    {
        string contentType = "Image/jpeg";



        byte[] data = this.FileServer("FileLocation");

        if (data == null)
        {
            return this.Content("No picture for this program.");
        }

        return File(data, contentType, img + ".jpg");
    }

Solution 4

With MVC I use a FileResult and return a FilePathResult

public FileResult ImageDownload(int id)
    {
        var image = context.Images.Find(id);
        var imgPath = Server.MapPath(image.FilePath);
        return File(imgPath, "image/jpeg", image.FileName);
    }

Solution 5

The correct way to download file in your case is to use FileResult class.

 public FileResult DownloadFile(string id)
{
try
{
    byte[] imageBytes =  ANY IMAGE SOURCE (PNG)
    MemoryStream ms = new MemoryStream(imageBytes);
    var image = System.Drawing.Image.FromStream(ms);
    image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
    var fileName = string.Format("{0}.png", "ANY GENERIC FILE NAME");
    return File(ms.ToArray(), "image/png", fileName);
}
catch (Exception)
{
}
return null;
}

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Comments

[Hugo Estrada]

Thanks. The content type was needed to force the download as a file.

[tierrarara]

content-type is a good solution, content disposition work too, but you can get some risk, exist another post about it stackoverflow.com/a/1012461/2062838

[jokab]

hey, me too! it turns out, we just needed to remove the filename so that your code will look like: return File(data, contentType)