参数字典包含非空类型'System.Int32的参数'restaurantId'的空条目

Question

Im new to stack overflow.I started to create an MVC application and instead of using a Map.Route I use a binding attribute to pass in the id. Below shows the error and the code for each class/components.

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

Model

public class ResturantReview
{
    public int Id { get; set; }
    public int Rating { get; set; }
    public string Body { get; set; }
    public string ReviewerName { get; set; }
    public int ResturantId { get; set; }

}

Controller
public class ResturantReviewsController : Controller
    {
        private OdeToFoodDb _db = new OdeToFoodDb();

        public ActionResult Index([Bind(Prefix = "id")] int restaurantId)
        {
            var restaurant = _db.Resturants.Find(restaurantId);
            if (restaurant != null)
            {
                return View(restaurant);
            }
            return HttpNotFound();
        }

        [HttpGet]
        public ActionResult Create(int restaurantId)
        {
            return View();
        }

        [HttpPost]
        public ActionResult Create(ResturantReview review)
        {
            if (ModelState.IsValid)
            {
                _db.Reviews.Add(review);
                _db.SaveChanges();
                return RedirectToAction("Index", new { id = review.ResturantId });
            }
            return View(review);
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                _db.Dispose();
            }
            base.Dispose(disposing);
        }

View

@model OdeToFood.Models.Resturant

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>
@Html.Partial("View", Model.Reviews)
<p>
    @Html.ActionLink("Create New", "Create", new { restaurantId = Model.Id })
</p>

Answer 1

From what is see you have action

 public ActionResult Index([Bind(Prefix = "id")] int restaurantId)

Remove Bind attribute

 public ActionResult Index(int id)

Bind prefix means that you POST/Get parameter as id.restaurantId. And you want to catch default routing which will read id from url like ResturantReviews/Index/2