怎样用session记住购物车内产品数量，并且将这个只写成标签返回给前台显示！有后台代码参考……

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {                if (Request.QueryString["ProductId"] != null)
                {
                    string Id = Request.QueryString["ProductId"].ToString();
                    try
                    {
                        decimal.Parse(Id);
                    }
                    catch
                    {
                        Response.Write("请不要从外部提交非法字串！！！");
                        return;
                    }
                    
                    //读取cookie
                    if (Request.Cookies["UserBus"] != null && Request.Cookies["UserBus"].Values.Count > 0)
                    {
                        HttpCookie cookie = Request.Cookies["UserBus"];
                        if (cookie.Values.ToString().IndexOf(Id) == -1)
                        {
                            cookie.Values.Add(Id, "'"+Id + "'$1");
                        }
                        cookie.Expires = DateTime.Now.AddDays(1);
                        Response.Cookies.Add(cookie);                    }
                    else
                    {
                        HttpCookie cookie = new HttpCookie("UserBus");//定义cookie对象以及名为Info的项
                        cookie.Values.Add(Id, "'"+Id + "'$1");
                        Response.AppendCookie(cookie);//确定写入cookie中
                    }
                }
                BindDropDownList();
                LoadDefault();
                BindDataGrid();            }        }                    //绑定gridView
        protected void BindDataGrid()
        {            string Ids = "";
            HttpCookie getcookie = Request.Cookies["UserBus"];
            string[] arr = new string[getcookie.Values.Count];
            for (int i = 0; i < getcookie.Values.Count; i++)
            {
                string value = getcookie.Values[i].ToString();
                Ids += value.Split('$')[0].ToString() + ",";
                arr[i] = value.Split('$')[1].ToString();
            }
            decimal productMoney = 0;//商品总价
            decimal CostPrice = 0; // 商品成本价
            int Weight = 0;//商品总重量
            int Number = 0;//商品总数量            DataTable dt = new DataTable();
            if (Ids.Length > 1)
            {
                int page = 0;
                int i, j;
                dt = NetCMS.Content.Search.getShopViewHistory(Ids.Substring(0, Ids.Length - 1), page, 15, out i, out j);                if (dt != null && dt.Rows.Count > 0)
                {
                    dt.Columns.Add("num", typeof(string));
                    dt.Columns.Add("money", typeof(decimal));
                    for (int k = 0; k < dt.Rows.Count; k++)
                    {
                        dt.Rows[k]["num"] = arr[k];
                        decimal money = Convert.ToDecimal(dt.Rows[k]["SalePrice"].ToString());
                        dt.Rows[k]["money"] = money * Convert.ToInt32(arr[k]);
                        productMoney += money * Convert.ToInt32(arr[k]);
                        CostPrice += Convert.ToDecimal(dt.Rows[k]["CostPrice"].ToString()) * Convert.ToInt32(arr[k]);
                        Weight += Convert.ToInt32(dt.Rows[k]["Weight"].ToString()) * Convert.ToInt32(arr[k]);
                    }
                }
            }            GridView1.DataSource = dt;
            GridView1.DataBind();            this.productMoney.Text = string.Format("{0:F2}",productMoney.ToString());
            this.Weight.Value = Weight + "";
            this.CostPrice.Value = CostPrice + "";
        }