public List<Model.EF_Model.Person> GetAll_List()
    {
        using (var contex = new ThirdTier.Model.EF_Model.TestEntities())
        {

                var a = contex.Person.Select(b => b)
                                  .OrderBy(b => b.Id).ToList();
                return a;

        }
    }

return a List<> method for using in UI Layer

dataGridView1.DataSource = a List<> Method From Business Layer