Why is my session in a view control null

Question

Hello, I'm trying to make a simple online journal, and I will get to the part where the user clicks the addtoCart button addtoCart

My model Cart has two properties - Product and quantity

 public class Cart { public ProductLanguages Product { get; set; } public int Quantity { get; set; } } 

So, in my basketViewModel in my AddProductToCart method AddProductToCart I add a product with the details that I get from the database in a property of type List. Then I save this list in the session. And if, for example, the user clicks the “continue shopping” button and returns to the index page - the next time he clicks “addtocart” for a new product, as you see, I do this check

 lstCarts = (List<Cart>)HttpContext.Current.Session["Cart"]; if (lstCarts==null) { lstCarts = new List<Cart>(); } 

At first I try to get the list from the session, so I can get previously saved products. But my session is always zero, so I always lose my previously purchased products. Curiously, I'm sure I saved the list of products on this line

  HttpContext.Current.Session["Cart"] = lstCarts; 

Here is my view model

  public class BasketViewModel { private readonly IProductLanguagesRepository prodlanRepository; public List<Cart> lstCarts { get; set; } public BasketViewModel() : this(new ProductLanguagesRepository()) { } public BasketViewModel(IProductLanguagesRepository prodlanRepository) { this.prodlanRepository = prodlanRepository; } public void CreateCart(int id,int quantity) { lstCarts = (List<Cart>)HttpContext.Current.Session["Cart"]; if (lstCarts==null) { lstCarts = new List<Cart>(); } ProductLanguages nwProduct = prodlanRepository.GetProductDetails(id); if (nwProduct != null) { Cart cr = new Cart(); cr.Product = nwProduct; cr.Quantity = quantity; lstCarts.Add(cr); HttpContext.Current.Session["Cart"] = lstCarts; } } } 

And my controller

  public class BasketManagementController : Controller { public ActionResult Index(int id, int quantity) { BasketViewModel vm = new BasketViewModel(); vm.CreateCart(id, quantity); return View(vm); } } 

Answer 1

You are misusing concepts:

* View model for the get and set properties object

* The controller is designed for operations with view model objects

Please try like this:

 //VIEW MODEL public class BasketViewModel{ public List<Cart> lstCarts { get; set; } } //CONTROLLER public class BasketManagementController : Controller { private IProductLanguagesRepository prodlanRepository; public BasketManagementController(IProductLanguagesRepository prodlanRepository){ this.prodlanRepository = prodlanRepository; } public ActionResult Index(int id, int quantity) { CreateCart(id, quantity); BasketViewModel vm = new BasketViewModel(); return View(vm); } public void CreateCart(int id,int quantity) { lstCarts = (List<Cart>)HttpContext.Current.Session["Cart"]; if (lstCarts==null) { lstCarts = new List<Cart>(); } ProductLanguages nwProduct = prodlanRepository.GetProductDetails(id); if (nwProduct != null) { Cart cr = new Cart(); cr.Product = nwProduct; cr.Quantity = quantity; lstCarts.Add(cr); HttpContext.Current.Session["Cart"] = lstCarts; } } } 

Answer 2

I have not seen any specific behavior. Maybe the problem with the line

ProductLanguages nwProduct = prodlanRepository.GetProductDetails(id);

There may be some exception with GetProductDetails (id)

Check this.