How to add Headers in HTTPContext Response in ASP.NET MVC 3?

Question

I have a download link in my page, to a file I generate by the user request. Now I want to display the file size, so the browser can display how much is left to download. As a solution, I guess addin a Header to the request would work, but now I don't know how to do it.

Here is my try code:

public FileStreamResult DownloadSignalRecord(long id, long powerPlantID, long generatingUnitID)
{
    SignalRepository sr = new SignalRepository();
    var file = sr.GetRecordFile(powerPlantID, generatingUnitID, id);
    Stream stream = new MemoryStream(file);

    HttpContext.Response.AddHeader("Content-Length", file.Length.ToString());

    return File(stream, "binary/RFX", sr.GetRecordName(powerPlantID, generatingUnitID, id) + ".rfx");
}

When I checked on fiddler, it didn't display the Content-Length header. Can you guys help me out?

Answer 1

Try using

HttpContext.Response.Headers.Add("Content-Length", file.Length.ToString());