Navigation property not getting filled on lazy loading - asp.net-mvc

Question

I am trying my hands-on on mvc examples given on Mvc Offical Site.
Here i have 3 Models Student,Course and Enrollment where there is an one to many relationship on Course and Enrollment entities and many to one relationship on Enrollment and student.
The models for Student,Course and Enrollment are as follows with the navigation properties marked as "virtual" since i need to perform lazy binding
public class Student
{
public int StudentID { get;set; }
public string LastName { get; set; }
public string FirstMidName { get; set; }
public DateTime EnrollmentDate { get; set; }
public virtual IEnumerable<Enrollment> Enrollments { get; set; }
}
In the same way i have my course model
My Enrollment Model
public class Enrollment
{
public int EnrollmentID { get; set; }
public int CourseID { get; set; }
public int StudentID { get; set; }
// public Grade? Grade { get; set; }
public virtual Course Course { get; set; }
public virtual Student Student { get; set; }
}
I am using Code-First Technique With EF 5.My DB Context Class is as follows
public class SchoolContext:DbContext
{
public DbSet<Student> Students { get; set; }
public DbSet<Enrollment> Enrollments { get; set; }
public DbSet<Course> Courses { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
By Scaffolding I have generated all my views .On Click of my details Action link I have a controller function that is called
public ActionResult Details(int id = 0)
{
db.Configuration.LazyLoadingEnabled = true;
db.Configuration.ProxyCreationEnabled = true;
Student student = db.Students.Find(id);
// db.Entry(student).Reference(p => p.Enrollments).Load();
IEnumerable<Enrollment> s= student.Enrollments;
if (student == null)
{
return HttpNotFound();
}
return View(student);
}
Here the problem is when the Find() method is called in the controller the navigation property in Student Class model is null.But there is data in DB corresponding to the id that is being passed.In short,the navigation property is not returning data(null).

Answer 1

You have to materialize the entities to get a rid of the current lazy loading in the query:
Student student = db.Students.Find(id).ToList();
This will fix your problem without ToList() after db.Students.Find(id); = will returns the generated object from the dynamic proxy.
Second problem you have a casting bug:
IEnumerable<Enrollment> enrollments = student.Enrollments; // is wrong
should be:
ICollection<State> enrollments = student.Enrollments;
or
var enrollments = student.Enrollments;