in my action method I used
ViewBag.type = new SelectList(
   db.UserDetails.AsEnumerable().GroupBy(x => x.type).Select(x => x.First()),
   "type",
   "type",
   user.type);
in my view I used
@Html.DropDownListFor(
   m => m.type,
   (IEnumerable<SelectListItem>)ViewBag.type,
   new { @class = "form-control" })
don't know whats wrong why not showing the selected item on load
 
     
    