Hello Everyone I am trying to add items to cart using Session But I am facing That issue System.NullReferenceException: Object reference not set to an instance of an object. Check This Image

Here is my View Where I want to show Cart items

 @foreach (var item in (List<Product>)Session["MyCart"])
                    {
                        
                        <li>
                            <a href="#" ><img src="@Url.Content(item.Product_Picture)"  alt="" /></a>
                            <h6><a href="#">@item.Product_Name </a></h6>
                            <p>1x -Rs <span >@item.Product_SalePrice</span></p>
                        </li>
                     
                    }
                </ul>

Now This is my Action Controller

public ActionResult AddtoCart(int id)
    {
        List<Product> list;
        if (Session["MyCart"] == null)
        { list = new List<Product>(); }
        else
        { list = (List<Product>)Session["MyCart"]; }
        list.Add(db.Products.Where(p => p.Product_ID == id).FirstOrDefault());
        Session["MyCart"] = list;
        return RedirectToAction("Shop");
    }

CodePudding user response：

You can check if your Session is not null on your View before you try to cast it and access its properties:

@if(Session["MyCart"] != null)
{
    foreach (var item in (List<Product>)Session["MyCart"])
    {
        
        <li>
            <a href="#" ><img src="@Url.Content(item.Product_Picture)"  alt="" /></a>
            <h6><a href="#">@item.Product_Name </a></h6>
            <p>1x -Rs <span >@item.Product_SalePrice</span></p>
        </li>
     
    }
    </ul>
}
else
{
    <h2>Cart is empty</h2>
}

You should create a partial view for your carts and then refer it where it is required. There are many tutorial for partial views creation and usage You can refer to this tutorial