ASP.NET MVC download image rather than display in browser

问题

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;
    }

回答1:

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

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

回答2:

You need to set the following headers on the response:

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

回答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");
    }

回答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);
    }

回答5:

This I actually @7072k3

var result = File(path, mimeType, fileName);
Response.ContentType = mimeType;
Response.AddHeader("Content-Disposition", "inline");
return result;

Copied that from my working code. This still uses the standard ActionResult return type.

回答6:

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;
}

来源：https://stackoverflow.com/questions/3007652/asp-net-mvc-download-image-rather-than-display-in-browser