asp.net mvc dropdownlist

1.controller:

 public class HomeController : Controller
    {
        //
        // GET: /Home/

        public ActionResult Index()
        {
            List<MyFileInfo> infoList = new List<MyFileInfo>();
            DirectoryInfo theFolder = new DirectoryInfo(Server.MapPath("~/Files/"));
            FileInfo[] fileInfo = theFolder.GetFiles();
            fileInfo.ToList().ForEach(e => {
                string filename=e.Name;
                infoList.Add(new MyFileInfo() {FileName=filename.Substring(0,filename.LastIndexOf(".")), FilePath="/Files/"+filename });
            });
            ViewBag.dataList = new SelectList(infoList, "FilePath", "FileName");
            return View(); 
        }

    }
    public class MyFileInfo
    {
        public string FileName { get; set; }
        public string FilePath { get; set; }
    }

2.cshtml:

 <div>
        @Html.DropDownList("FileList", ViewBag.dataList as SelectList, "--请选择--", new { width="auto" })
 </div>