list转为json

   public ActionResult tb()
   {
     ArrayList list = new ArrayList();
    list.Add(stufile);
     return new ContentResult
      {
         Content = new JavaScriptSerializer { MaxJsonLength = Int32.MaxValue }.Serialize(list),
         ContentType = "application/json"
     };

    public class stuReadFile
    {
        public string file_name;
        public string belong;
        public string size;
        public string create_time;
        public string fpath;
    }