Null id value in MVC 4 Controller

Question

I am developing an MVC 4 internet application and am having trouble after I am creating an object.

Here is the code where the error is happening:

[Authorize]
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(int id, Comment comment)
{
    if (ModelState.IsValid)
    {
        Book book = db.books.Where(b => b.id == id).First();
        comment.username = us.GetCurrentlyLoggedInUserName();
        book.comments.Add(comment);
        db.SaveChanges();
        return RedirectToAction("Index", id);
    }

    return View(comment);
}

Here is the Index ActionResult:

public ActionResult Index(int id)
{
    var commentsBookViewModel = new CommentsViewModel();
    commentsBookViewModel.bookId = id;
    commentsBookViewModel.isUserLoggedIn = us.IsUserLoggedIn();
    commentsBookViewModel.loggedInUserName = us.GetCurrentlyLoggedInUserName();
    commentsBookViewModel.comments = db.books.Where(b => b.id == id).FirstOrDefault().comments.ToList();
    return View(commentsBookViewModel);
}

Here is the error:

The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult Index(Int32)' in 'BookApplication.Controllers.CommentController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter. Parameter name: parameters

If I place a break point at the line:

return RedirectToAction("Index", id);

The variable id has a value, and is not null, yet the error still occurs.

Can I please have some help with this?

Thanks in advance

Answer 1

I would try passing it with something like this.

return RedirectToAction("Index", new { id = id});