public IActionResult Index(IndexViewModel vm)
 {
     if (ModelState.IsValid)
     {
         string webrootPath = _hostEnvironment.WebRootPath;
         var    result      = new IndexViewModel
         {
             Files       = _upload.GetUploadFiles(vm.Email, vm.TransNumber),
             href        = webrootPath,
             UploadNames = _upload.GetUploadDocs()
         };
         return(View(result));
     }
     return(View(vm));
 }