ASP.NET购物车代码程序

    这是一个ASP.net购物车的代码程序.
    using System;
    using System.Data;
    using System.Configuration;
    using System.Collections;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Web.UI.HtmlControls;

    public partial class cart : System.Web.UI.Page
    {
        public MyDb dd = new MyDb();
        public string AddProID;
        protected string RefreshID;
      //  public string total;
        protected void Page_Load(object sender, EventArgs e)
        {

                if (!Page.IsPostBack)
                {
                    //if (RefreshID == "")
                    //{
                    //    RefreshID =System.DateTime.Now.Ticks.ToString();
                    //}
                    if (Request.Params["mode"] == "view")         //检测是否为直接查看购物车。
                    {
                        ViewShoppingCart();
                        Caculator();
                    }
                    if (Request.Params["productID"] != null || Request.Params["productID"] != "")
                    {
                        this.rnd.Text = Request["item"];
                        AddProID = Request["productID"];
                        UpdateShoppingCart();

     Caculator();
                    }
                }

        }
        public void CreateCartTable()   //创建购物车
        {
            DataSet ds = new DataSet();
            DataTable newDT = new DataTable("CartTable");
            ds.Tables.Add(newDT);
            DataColumn newDC;
            newDC = new DataColumn("ProductID", System.Type.GetType("System.Int32"));
            ds.Tables["CartTable"].Columns.Add(newDC);

            newDC = new DataColumn("Name", System.Type.GetType("System.String"));
            newDC.DefaultValue = 1;
            ds.Tables["CartTable"].Columns.Add(newDC);

            newDC = new DataColumn("max", System.Type.GetType("System.String"));
            ds.Tables["CartTable"].Columns.Add(newDC);

            newDC = new DataColumn("Unit", System.Type.GetType("System.String"));
            ds.Tables["CartTable"].Columns.Add(newDC);

            newDC = new DataColumn("SellPrice", System.Type.GetType("System.Int32"));
            ds.Tables["CartTable"].Columns.Add(newDC);

            newDC = new DataColumn("IsDeleted", System.Type.GetType("System.Int32"));
            newDC.DefaultValue = 0;
            ds.Tables["CartTable"].Columns.Add(newDC);
            Session["myCartTable"] = newDT;
            ShoppingCartDlt.DataSource = ds.Tables["CartTable"].DefaultView;
            ShoppingCartDlt.DataBind();

        }
        public void UpdateShoppingCart()
        {
            if (Session["myCartTable"] == null)//Session["myCartTable"]==null

            {
                CreateCartTable();                                    //调用函数CreateCartTable()新建一个DataTable
                WriteShoppingCart();
            }
            else
            {                                                         //如果购物蓝中已有商品，则需要对购物信息表DataTable进行更新，并将其棒定到                                                                             ShoppingCartDlt
                WriteShoppingCart();
            }
        }

        public void ViewShoppingCart()                               //查看购物车
        {
            if (Session["myCartTable"] != null)
            {
                DataTable viewTable = new DataTable("nowCartTable");
                viewTable = (DataTable)Session["myCartTable"];
                ShoppingCartDlt.DataSource = viewTable.DefaultView;         //购物车棒定到ShoppingCartDlt
                ShoppingCartDlt.DataBind();
     }