How to set downloading file name in ASP.NET Web API

Question

In my ApiController class, I have following method to download a file created by server.

public HttpResponseMessage Get(int id)
{
    try
    {
        strin         


        

Answer 1

You need to add the content-disposition header to the response:

 response.StatusCode = HttpStatusCode.OK;
 response.Content = new StreamContent(result);
 response.AppendHeader("content-disposition", "attachment; filename=" + fileName);
 return response;

Answer 2

If you want to ensure that the file name is properly encoded but also avoid the WebApi HttpResponseMessage you can use the following:

Response.AddHeader("Content-Disposition", new System.Net.Mime.ContentDisposition("attachment") { FileName = "foo.txt" }.ToString());

You may use either ContentDisposition or ContentDispositionHeaderValue. Calling ToString on an instance of either will do the encoding of file names for you.

Answer 3

EDIT: As mentioned in a comment, My answer doesn't account for characters that need to be escaped like a ;. You should use the accepted answer Darin made if your file name could contain a semi-colon.

Add a Response.AddHeader to set the file name

Response.AddHeader("Content-Disposition", "attachment; filename=*FILE_NAME*");

Just change FILE_NAME to the name of the file.