Should i instantiate a new model?

Question

MVC. I am passing data to the view in my model. In my repository I map the linq result to the model. In the controller I send the data. Which one should I do:

List<PersonModel> people = new List<PersonModel>();
people = repo.GetPersonList();
return View(people);

Or

List<PersonModel> people = repo.GetPersonList();
return View(people);

As I mentioned, in the repo I map the result to the model, with a new model instance:

var query = from p in _db.Person
                     orderby f.LastName
                     select new PersonModel
                     {
                         Id = f.PersonId,
                         LastName = f.LastName
                     };
return query.ToList();

Either one works. I use the second one because by my thinking, the repo is creating a new model then passing it to the controller when I call the repo.GetPersonList function. Should I create a new instance in the controller as well, or continue as I am?

Answer 1

Go with the second.

Your first snippet has a redundant new List<T> call which allocates a new list, while the next line overrides that reference with a newly created list from your repo . Absolutely no need for that.

Answer 2

如果在您的Controller上， repository负责提供ViewModel并且您没有允许Controller将新的PersonModel添加到ViewModel，那么您应该坚持使用第二个 。