Download Project  (Full Project)

Step-1

In this tutorial we solve the quantity problem. When we add same product then the product name will be same but quantity are change in the cart section. Now we will solve the duplicate entry. By the “AddToCart()” method. This method are chack the duplication entry and quantity. And assign the list and show the view page. also when remove the product then it delete the product from the list and refresh the view. We have to few change in controller then we get the result.In this  cart.Add() method is increment the prduct quentity but name well be same. Given bellow the Controller  source code:

using Newtonsoft.Json;
using OnlineShoppingStore.DAL;
using OnlineShoppingStore.Models;
using OnlineShoppingStore.Models.Home;
using OnlineShoppingStore.Repository;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace OnlineShoppingStore.Controllers
{
    public class HomeController : Controller
    {
        dbMyOnlineShoppingEntities ctx = new dbMyOnlineShoppingEntities();
        public ActionResult Index(string search,int? page)
        {
            HomeIndexViewModel model = new HomeIndexViewModel();
            return View(model.CreateModel(search,4, page));
        }

        public ActionResult AddToCart(int productId)
        {
            if (Session["cart"] == null)
            {
                List<Item> cart = new List<Item>();
                var product = ctx.Tbl_Product.Find(productId);
                cart.Add(new Item()
                {
                    Product = product,
                    Quantity = 1
                });
                Session["cart"] = cart;
            }
            else
            {
                List<Item> cart = (List<Item>)Session["cart"];
                var product = ctx.Tbl_Product.Find(productId);
                foreach (var item in cart)
                {
                    if (item.Product.ProductId == productId)
                    {
                        int prevQty = item.Quantity;
                        cart.Remove(item);
                        cart.Add(new Item()
                        {
                            Product = product,
                            Quantity = prevQty+1
                        });
                        break;
                    }
                    else
                    {
                        cart.Add(new Item()
                        {
                            Product = product,
                            Quantity = 1
                        });
                    }
                }
                Session["cart"] = cart;
            }
            return Redirect("Index");
        }
        public ActionResult RemoveFromCart(int productId)
        {
            List<Item> cart = (List<Item>)Session["cart"];
            foreach (var item in cart)
            {
                if (item.Product.ProductId == productId)
                {
                    cart.Remove(item);
                    break;
                }
            }
            Session["cart"] = cart;
            return Redirect("Index");
        }
    }
}

Step-3

Now run the project.