1. ## Upload File

       ////Upload
       [HttpPost]
       public JsonResult UpFile()
       {

           if (Request.Files.Count == 0 || Request.Files[0] == null)
           {
               return Json(new { status = 0, message = "Not fle to upload" });
           }
           HttpPostedFileBase file = Request.Files[0];

           string filename = "mynamefile";///name file save

           try
           {
               if (Request == null)
               {
                   return null;
               }

               //Path to save file
               var dpath = Server.MapPath("~/Upload");
               var postedFile = file;
               if (postedFile != null)
               {
                   if (!Directory.Exists(dpath))
                   {
                       Directory.CreateDirectory(dpath);
                   }
                   string ext = Path.GetExtension(postedFile.FileName);
                   if (!String.IsNullOrEmpty(ext))
                   {
                       filename += ext; ///EX: "namefile.pdf"
                       postedFile.SaveAs(dpath + "/" + filename);
                   }
               }
           }
           catch (Exception)
           {
               filename = "";
               return Json(new { data = filename, status = 0, message = "Err" });
           }

           return Json(new { data = filename, status = 1, message = "OK" });
       }

2. ## Download File

<!--HTML-->. <a href="/MyController/DownloadFile/{{Item.NameFile}}" target="_blank" class="bold form-control-static font-blue-hoki"> {{Item.NameFile}} </a> <!--HTML-->.

         ///code C# Downloadfile
        [HttpGet]
        public ActionResult DownloadFile(string namefile)
        {
            string nameDisplay = "";//name replace
            HttpRequestMessage request = new HttpRequestMessage();
            try
            {

                string baseFolder = "~/Upload";///path 
                string[] sElement = namefile.Split('.');
                int vt = sElement.Length - 1;

                nameDisplay +=   "." + sElement[vt];
                if (!string.IsNullOrEmpty(fileName))
                {

                    string path = Server.MapPath(baseFolder + fileName);
                    var bytes = System.IO.File.ReadAllBytes(path);

                    return File(bytes, "application/octet-stream", nameDisplay);
                }

                return Content("File not found");
            }
            catch (Exception)
            {
                return Content("Download Err");
            }
        }