public void AddToCart(int id)
        {
            // Retrieve the product from the database.           
            ShoppingCartId = GetCartId();

            var cartItem = _db.ShoppingCartItems.SingleOrDefault(
                c => c.CartId == ShoppingCartId
                && c.ProductId == id);
            if (cartItem == null)
            {
                // Create a new cart item if no cart item exists.                 
                cartItem = new CartItem
                {
                    ItemId = Guid.NewGuid().ToString(),
                    ProductId = id,
                    CartId = ShoppingCartId,
                    Product = _db.Products.SingleOrDefault(
                   p => p.ProductID == id),
                    Quantity = 1,
                    DateCreated = DateTime.Now
                };

                _db.ShoppingCartItems.Add(cartItem);
            }
            else
            {
                // If the item does exist in the cart,                  
                // then add one to the quantity.                 
                cartItem.Quantity++;
            }
            _db.SaveChanges();
        }

 public bool AddToCartAsync(int cartId, int ProductID)
 {
     myHandler = new BusinessLogicHandler();
     item = new CartItem();
     item = myHandler.CheckIfExist(cartId, ProductID);
     if(item == null)
     {
         item = new CartItem();
         item.CartID = cartId;
         item.ProductID = ProductID;
         item.DateAdded = DateTime.Now;
         item.Quantity = 1;
         if (myHandler.AddCartItem(item))
         { return true; }
         else
             return false;
     }
     else
     {
         item.Quantity += 1;
         if (myHandler.UpdateCartItem(item))
         { return true; }
         else
             return false;
     }
 }

    /**
     * AddItem() - Adds an item to the shopping
     */
    public void AddItem(int productId, int kolicina)
    {
        if (HttpContext.Current.Session["ASPNETShoppingCart"] == null)
        {
            ShoppingCart Instance;
            Instance = new ShoppingCart();
            Instance.Items = new List<CartItem>();
            HttpContext.Current.Session["ASPNETShoppingCart"] = Instance;
        }

        // Create a new item to add to the cart
        CartItem newItem = new CartItem(productId);

        // If this item already exists in our list of items, increase the quantity
        // Otherwise, add the new item to the list
        if (Items.Contains(newItem))
        {
            foreach (CartItem item in Items)
            {
                if (item.Equals(newItem))
                {
                    item.Quantity = item.Quantity + kolicina;
                    return;
                }
            }
        }
        else
        {
            newItem.Quantity = kolicina;
            Items.Add(newItem);
        }
    }

    protected void btnAdd_Click(object sender, EventArgs e)
    {
        selectedProduct = new Product();
        this.selectedProduct.Course_id = course_id.ToString();

        if (Page.IsValid)
        {
            CartItemList cart = CartItemList.GetCart();
            int locCount = cart.Count;
            locCount = locCount + 1;
            this.selectedProduct.assignmentNumber = locCount.ToString();
            this.selectedProduct.aGUID = Guid.NewGuid().ToString();
            this.selectedProduct.Num_Assignment = locCount;
            CartItem cartItem = new CartItem();

            int Num_Assignments=0;
            int assignment = 1; //will be produced from loop according to Num_Assignments
            cart = CartItemList.GetCart();
            cartItem = cart[selectedProduct.Course_id];

            if (cartItem == null)
            {
                cart.AddItem(selectedProduct, Num_Assignments,assignment);
            }
            else
            {
                cart.AddItem(selectedProduct, Num_Assignments, assignment);
                cartItem.AddQuantity(1);
            }
            this.DisplayCart();

        }
    }

        /**
     * AddItem() - Adds an item to the shopping 
     */
        public void AddItem(int productId, string productName, int productQuantity, decimal productPrice)
        {
            // Create a new item to add to the cart
            CartItem newItem = new CartItem(productId, productName, productQuantity, productPrice);

            // If this item already exists in our list of items, increase the quantity
            // Otherwise, add the new item to the list
            if (Items.Contains(newItem))
            {
                foreach (CartItem item in Items)
                {
                    if (item.Equals(newItem))
                    {
                        //item.ProductQuantity++;
                        item.ProductQuantity += productQuantity;
                        return;
                    }
                }
            }
            else
            {
                //newItem.ProductQuantity = 1;
                Items.Add(newItem);
            }
        }

		/// <summary>
		/// Add an item to the cart.
		/// When ItemId to be added has already existed, this method will update the quantity instead.
		/// </summary>
		/// <param name="itemId">Item Id of item to add</param>
		public void Add(string itemId)
		{
			CartItem cartItem;

			if (!_items.TryGetValue(itemId, out cartItem))
			{
				Item item = new ProductManager().GetItem(itemId);

				if (item != null)
				{
					cartItem = new CartItem();

					cartItem.ItemID     = itemId;
					cartItem.Name       = item.ProductName;
					cartItem.Price      = (decimal)item.Price;
					cartItem.Type       = item.Name;
					cartItem.CategoryID = item.CategoryID;
					cartItem.ProductID  = item.ProductID;

					_items.Add(itemId, cartItem);
				}
			}

			cartItem.Quantity++;
		}

        public void AddItem(CartItem item)
        {
            if (Items.Contains(item))
                return;

            Items.Add(item);
        }

        public void AddToCart(Product product, decimal price)
        {
            // Get the matching cart and product instances
            var cartItem = db.CartItems.SingleOrDefault(
                c => c.CartID == ShoppingCartId
                && c.ProductID == product.ProductID);

            if (cartItem == null)
            {
                // Create a new cart item if no cart item exists
                cartItem = new CartItem
                {
                    ProductID = product.ProductID,
                    CartID = ShoppingCartId,
                    Amount = 1,
                    Price = price,
                    Creation = DateTime.Now
                };

                db.CartItems.AddObject(cartItem);
            }
            else
            {
                // If the item does exist in the cart, then add one to the quantity
                cartItem.Amount++;
            }

            // Save changes
            db.SaveChanges();
        }

        public void Comparer_DifferentInstancesWithSameValues_ReturnsTrue()
        {
            Guid memberId = new Guid("3E522B6E-9F75-4E9A-BB11-52CE00827977");
            Guid productId = new Guid("6C7133F7-143A-4CF1-90C5-8661A4AC6B87");
            int quantity = 4;
            bool isNew = true;

            CartItem item1 = new CartItem
            {
                IsNew = isNew,
                MemberId = memberId,
                ProductId = productId,
                Quantity = quantity
            };
            CartItem item2 = new CartItem
            {
                IsNew = isNew,
                MemberId = memberId,
                ProductId = productId,
                Quantity = quantity
            };

            bool result = CartItem.CartItemComparer.Equals(item1, item2);

            Assert.That(result, Is.True);
        }

        public void AddToCart(int Id)
        {
            ShoppingCartId = GetCartid();

            var cartitem = db.CartItems.SingleOrDefault(p => p.CartId == ShoppingCartId && p.ProductId == Id);

            if (cartitem == null)
            {
                cartitem = new CartItem
                {
                    ItemId = Guid.NewGuid().ToString(),
                    CartId = GetCartid(),
                    Quantity = 1,
                    CreateDate = DateTime.Now,
                    Product = db.Products.SingleOrDefault(p => p.Id == Id),
                    ProductId = Id
                };
                db.CartItems.Add(cartitem);
            }
            else
            {
                cartitem.Quantity++;
            }
            db.SaveChanges();
        }

        public CartItem AddToCart(long userId, long productId, string variationName, int quantity)
        {
            var cartItemQuery = cartItemRepository
                .Query()
                .Include(x => x.Product)
                .Where(x => x.ProductId == productId && x.UserId == userId);

            var cartItem = cartItemQuery.FirstOrDefault();

            if (cartItem == null)
            {
                cartItem = new CartItem
                {
                    UserId = userId,
                    ProductId = productId,
                    Quantity = quantity,
                    CreatedOn = DateTime.Now
                };

                cartItemRepository.Add(cartItem);
            }
            else
            {
                cartItem.Quantity = quantity;
            }

            cartItemRepository.SaveChange();

            return cartItem;
        }

 public CartItemViewModel(CartItem cartItem)
 {
     ItemID = cartItem.ItemID;
     //SeasonNo = "NA";
     Category = cartItem.ItemCategory;
     QuantityRequired = cartItem.NoOfCopies;
     AmountPerItem = cartItem.Cost;
 }

        public void Comparer_SameInstance_ReturnsTrue()
        {
            CartItem item = new CartItem();

            bool result = CartItem.CartItemComparer.Equals(item, item);

            Assert.That(result, Is.True);
        }

        public void RemoveItem_should_remove_item_from_shopping_cart()
        {
            var cartItem = new CartItem();
            _shoppingCart.AddItem(cartItem);
            _shoppingCart.RemoveItem(cartItem);

            Assert.IsEmpty(_shoppingCart.CartItems);
        }

    protected void addToCart1_Click(object sender, EventArgs e)
    {
        //
        CartItem newItem = new CartItem(name, price, itemPic, type,
                            quantity, total, mPrice, dayDelivered, discount, prod_id);

        // Add Current product to Shopping cart when button clicked
        Profile.ShoppingCart.Items.Add(newItem);
    }

        public ActionResult Add(string productId)
        {
            var product = this.catalogService.GetProduct(productId);
            var cart = this.GetCurrentCart();
            var item = new CartItem { Id = product.Id, Name = product.Name, Price = product.Price };
            cart.Add(item);

            return this.Index();
        }

    public CartItem[] GetItems()
    {
        CartItem[] items = new CartItem[cart.Count];

        for (int i = 0; i < cart.Count; i++)
            items[i] = (CartItem) cart.GetByIndex(i);

        return items;
    }

    protected void btnAccept_Click(object sender, EventArgs e)
    {
        CCEncrypt cce = new CCEncrypt();
        string ccencrypted = cce.EncryptTripleDES(txtCardNumber.Text, "aptech");
        ccservice.Service ccser = new ccservice.Service();
        bool valid = ccser.CheckCC(ccencrypted).CardValid;
        string ct = ccser.CheckCC(ccencrypted).CardType;
        if (valid == true)
        {
            Label9.Visible = false;
            int id = 1;
            DateTime datetime = DateTime.Now;
            SqlConnection con = DBConnection.getConnection();
            SqlCommand cmd = new SqlCommand("INSERT INTO Orders VALUES ((SELECT Customer.CustomerID FROM Customer WHERE Customer.UserName = @UserName), @PaymentMethodID, @OrderTime, @ShippingAddress, @PaymentDetail, @TotalPrice, @OrderStatus)", con);
            cmd.Parameters.Add(new SqlParameter("@UserName", Request.Cookies["UserName"].Value));
            cmd.Parameters.Add(new SqlParameter("@PaymentMethodID", id));
            cmd.Parameters.Add(new SqlParameter("@OrderTime", datetime));
            cmd.Parameters.Add(new SqlParameter("@ShippingAddress", txtAddress3.Text));
            cmd.Parameters.Add(new SqlParameter("@PaymentDetail", ct));
            cmd.Parameters.Add(new SqlParameter("@TotalPrice", Int32.Parse(Cart.Instance.GetSubTotal().ToString())));
            cmd.Parameters.Add(new SqlParameter("@OrderStatus", "Pending"));
            cmd.ExecuteNonQuery();
            con.Close();

            IEnumerator enm = Cart.Instance.Items.GetEnumerator();
            while (enm.MoveNext())
            {
                Object obj = enm.Current;
                CartItem item = new CartItem();
                item = (CartItem)obj;

                SqlDataReader dr;
                SqlConnection con1 = DBConnection.getConnection();
                SqlCommand cmd1 = new SqlCommand("INSERT INTO OrderDetails VALUES (@OrderID, @ImageUrl, @RES, @Quantity, @TPrice)", con1);
                SqlCommand cmd2 = new SqlCommand("SELECT TOP 1 * FROM Orders Order BY OrderID DESC", con1);
                dr = cmd2.ExecuteReader();
                while (dr.Read())
                {
                    cmd1.Parameters.Add(new SqlParameter("@OrderID", dr["OrderID"]));
                }
                dr.Close();
                cmd1.Parameters.Add(new SqlParameter("@ImageUrl", item.ImageUrl));
                cmd1.Parameters.Add(new SqlParameter("@RES", item.Res));
                cmd1.Parameters.Add(new SqlParameter("@Quantity", item.Quantity));
                cmd1.Parameters.Add(new SqlParameter("@TPrice", item.TotalPrice));
                cmd1.ExecuteNonQuery();
                con1.Close();

            }
            Cart.Instance.RemoveCart();
            MultiView1.ActiveViewIndex = 0;
        }
        else
        {
            Label9.Visible = true;
        }
    }

 // Set item quantity
 public void SetItemQuantity(int id, int quantity)
 {
     CartItem updateItem = new CartItem(id);
     foreach (var item in Items)
         if (updateItem.Equals(item))
         {
             item.Quantity = quantity;
             return;
         }
 }

        public void ChangeQuantityNegativeFailsTest()
        {
            var cartItem = new CartItem
            {
                ArticleNumber = "ART1",
                Quantity = 1
            };

            cart.AddItem(cartItem);
            cart.ChangeQuantity(cartItem.Id, -2m);
        }