关于一个购物车的问题

Question

我把购买的商品放到一个cookie里面
代码如下：
protected void rplist_ItemCommand(object source, RepeaterCommandEventArgs e)
    {
        if (e.CommandName == "buy")
        {
            string priductID = e.CommandArgument.ToString();
            Label lbpn = (Label)e.Item.FindControl("lbpn");
            Label lbpi = (Label)e.Item.FindControl("lbpi");
            Label lbpp = (Label)e.Item.FindControl("lbpp");            if (Request.Cookies["priduct"] != null)
            {
                string cookieValue = "";
                if (Request.Cookies["priduct"].Value.Contains(','))
                {
                    string[] str = Request.Cookies["priduct"].Value.Split(',');
                    int m = 0;
                    for (int i = 0; i < str.Length - 1; i++)
                    {
                        string[] value = str[i].Split('|');
                        string c = value[2];
                        if (c == priductID)
                        {
                            m = 1;
                            cookieValue += value[0] + "|" + value[1] + "|" + value[2] + "|" + value[3] + "|" +  (int.Parse(value[4]) + 1).ToString() + ",";
                        }
                        else
                        {
                            cookieValue += value[0] + "|" + value[1] + "|" + value[2] + "|" + value[3] + "|" +  value[4] + "";
                        }
                    }
                    if (m == 0)
                    {
                        string s = Request.Cookies["priduct"].Value + lbpn.Text + "|" + lbpi.Text + "|" + priductID + "|" + lbpp.Text + "|1|" + ",";
                        Response.Cookies["priduct"].Value = s;
                    }
                    else
                    {
                        Response.Cookies["priduct"].Value = cookieValue;
                    }
                }
            }
            else
            {
                HttpCookie hc = new HttpCookie("priduct");
                Response.Cookies.Add(hc);
                hc.Value = lbpn.Text + "|" + lbpi.Text + "|" + priductID + "|" + lbpp.Text + "|1|" + ",";
            }
            Response.Redirect("GuWuChe.aspx");
        }
    }然后再到另外一个页面取cookie
代码如下：
protected void Page_Load(object sender, EventArgs e)
    {
        AddProduct_Intro();
    }
    private void AddProduct_Intro()
    {
        int money = 0;
        ArrayList list = new ArrayList();
        if (Request.Cookies["priduct"] != null)
        {
            string[] carid = Request.Cookies["priduct"].Value.Split(',');
            for (int i = 0; i < carid.Length - 1; i++)
            {
                string[] cards = carid[i].Split('|');
                Product_Introes pi = new Product_Introes();
                pi.ProductName = cards[0];
                pi.Product_Intro = cards[1];
                pi.Product_Price = int.Parse(cards[3]);
                pi.Amount = int.Parse(cards[4]);
                money += int.Parse(cards[3]) * int.Parse(cards[4]);
                list.Add(pi);
            }        }
        rplist.DataSource = list;
        rplist.DataBind();
        lbMoneySum.Text = money.ToString();    }
//清空购物车
    protected void lbtnqingkong_Click(object sender, EventArgs e)
    {
        if (Request.Cookies["priduct"] != null)
        {
            Response.Cookies["priduct"].Value = null;
        }
    }
问题   我清空购物车了  再点购买的时候就购买不了了！！！请哪位高手指点下  谢谢！！！！

Answer 1

购物车一般放入session比较好。

Answer 2

using System;
using System.Data;
using System.Configuration;
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;
using System.Data.SqlClient;/// <summary>
///     cookie操作购物车的类  确实订单时连接数据库太频繁需要进行优化
/// </summary>
public class ShoppingManage
{
    public ShoppingManage()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
   // public static HttpCookie hc = null;
    public static String CookieName = "SHOPPING_INFO";    /// <summary>
    /// 添加商品进购物车
    /// </summary>
    /// <param name="productId"></param>
    /// <param name="num"></param>
    /// <returns></returns>
    public static bool AddProduct(int productId,int num)
    {
        HttpCookie hc = null;
        String oldCookieValue;
        String NewValue;
        hc = HttpContext.Current.Request.Cookies[CookieName];
        if (hc == null)             //如果Cookie不存在 则直接新建Cookie 保存商品id和数量;
        {
            hc = new HttpCookie(CookieName);
            hc.Expires = DateTime.Now.AddDays(7);
            hc.Value = productId.ToString() + "|" + num.ToString();
                    }
        else  //假设Cookie存在 则处理
        {
            oldCookieValue = hc.Value;
             NewValue=AddCookieValue(oldCookieValue,productId,num);
             hc.Value = NewValue;        }
        HttpContext.Current.Response.AppendCookie(hc); //Cookie写入Response 
        return true;                //结束
    }
    /// <summary>
    /// 已存在Cookie则追加商品
    /// </summary>
    /// <param name="Value"></param>
    /// <param name="NewProductId"></param>
    /// <param name="Num"></param>
    private static string AddCookieValue(string Value, int NewProductId, int Num)
    {
        String NewValue="";
        bool IsAdd = false;
        string[] productList = Value.Split(',');
        for (int i = 0; i < productList.Length; i++)
        {
            string[] productInfo = productList[i].Split('|');
            if (productInfo[0] == NewProductId.ToString())
            {
                IsAdd = true;
                NewValue += productInfo[0] + "|"+((int.Parse(productInfo[1])) + Num).ToString()+",";
            }
            else
            {
                NewValue += productInfo[0] + "|" + productInfo[1] + ",";
            }        }
        if (IsAdd)
        {            NewValue = NewValue.Substring(0, NewValue.Length - 1);
        }
        else
        {
            NewValue += NewProductId.ToString() + "|" + Num.ToString();
        }        return NewValue;
    }    /// <summary>
    /// 获取购物车信息
    /// </summary>
    /// <returns></returns>
    public static string  GetShoppingInfo()
    {
        HttpCookie hc = null;
        String oldCookieValue;
        hc = HttpContext.Current.Request.Cookies[CookieName];
        if (hc == null)             //如果Cookie不存在 则直接新建Cookie 保存商品id和数量;
        {
            return null;
        }
        else
        {
            return hc.Value;
        }
    }   }

Answer 3

session也有问题  .net有回收机制 ！！ 有时候会出问题的