asp里想用vb.net写一个购物车

 Dictionary<int, DishesSession> dishes = new Dictionary<int, DishesSession>();DishesSession--你定义的商品实体类
                if (Session["cart"] != null)
                {
                    dishes = Session["cart"] as Dictionary<int, DishesSession>;
                }
                //判断集合中是否存在该商品，如果存在，则数量+1，否则添加
                if (dishes.ContainsKey(model.Id))
                {
                    dishes[model.Id].Count++;
                }
                else
                {
                    dishes.Add(model.Id, model);
                }
                //将购物购物信息保存到Session中
                Session["cart"] = dishes;