MVC返回文件

public void Index()
{
    var path = Server.MapPath("~/Content/Site.css");
    using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
    {
        byte[] bytes = new byte[(int)fs.Length];
        fs.Read(bytes, 0 , bytes.Length);
        fs.Close();

        Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode("Site.css"));
        Response.AddHeader("Content-Length", bytes.Length.ToString());
        Response.BinaryWrite(bytes);

        Response.Flush();
    }
}

public ActionResult Get()
{
    var path = Server.MapPath("~/Content/Site.txt");
    return File(new FileStream(path, FileMode.Open), "text/plain", HttpUtility.UrlEncode("Site.txt"));
}