how to store view model value to session - asp.net

Question

i already try to store my viewmodel to session.
i store my database to viewmodel, and i want to save viewmodel value to session
i try to use
List<GetUserNameViewModel> getName = _accountService.GetLoginName(UserID)
Session["GetName"] = getName;
but value is
System.Collections.Generic.List`1[XNet.Repository.Model.GetUserNameViewModel], not Username...
how can i save my viewmodel value to session??
this my service
public List<GetUserNameViewModel> GetLoginName(int UserID)
{
List<User> user = (from d in _UserRepository.All()
where d.UserID == UserID
select d).ToList();
List<GetUserNameViewModel> GetName = new List<GetUserNameViewModel>();
foreach (User users in user)
{
GetName.Add(new GetUserNameViewModel
{
UserName = users.UserName
});
}
return GetName;
}
my controller
public ActionResult Index()
{
int UserID = Convert.ToInt32(User.Identity.Name);
List<GetUserNameViewModel> getName = _accountService.GetLoginName(UserID);
Session["GetName"] = getName;
return View();
}

Answer 1

In the View (Razor), you've to cast the object in order to traverse the List<T> if that list has two or more GetUserNameViewModel object references or just call FirstOrDefault() method to read the first or default element from the List<T>,
#{
List<GetUserNameViewModel> getNames = Session["GetName"] as List<GetUserNameViewModel>;
for(var name in getNames){
//statements
}
//Or
GetUserNameViewModel name = getNames.FirstOrDefault();
}
And in other case, change the GetLoginName method. I think GetLoginName method should returns an object not a List<T>.
public GetUserNameViewModel GetLoginName(int UserID)
{
User user = (from d in _UserRepository.All()
where d.UserID == UserID
select d).FirstOrDefault();
if(user==null)
return null;
return new GetUserNameViewModel() { UserName = user.UserName };
}