Download Text File in asp.net

StringWriter oStringWriter = new StringWriter();
        Response.ContentType = "text/plain";
        Response.AddHeader("Content-Disposition", "attachment; filename=YourFileName.txt");
        Response.Clear();
        using (StreamWriter writer = new StreamWriter(Response.OutputStream, Encoding.UTF8))
        {
            writer.Write("This is the content");
        }
        Response.End();