C#基于cookie实现的购物车功能

HttpCookie cookie = new HttpCookie("shop");
//cookie.values集合能够存储多个键值对，其中add方法的第一个参数是商品编号，第二个参数是商品名称和价格，中间用都好分隔。
cookie.Values.Add("1", "电脑,2000");
cookie.Values.Add("2", "电视,2200");
cookie.Values.Add("3", "冰箱,2300");
cookie.Expires = DateTime.Now.AddDays(1);
Response.Cookies.Add(cookie);

/// <summary>
/// 显示购物车
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button2_Click(object sender, EventArgs e)
{
  LoadShop();
}
//显示购物车
private void LoadShop()
{
  //首先判断名称为"shop"的cookie是否存在
  if (Request.Cookies["shop"] != null)
  {
    HttpCookie cookie = Request.Cookies["shop"];
    StringBuilder sb = new StringBuilder();
    sb.Append("<table>");
    //便利此cookie的values集合，取出每一个键值对
    for (int i = 0; i < cookie.Values.Count; i++)
    {
      sb.Append("<tr>");
      sb.Append("<td>");
      sb.Append("<a href=WebForm5.aspx?id=" + cookie.Values.AllKeys[i] + ">删除<a/>");
      sb.Append("</td>");
      sb.Append("<td>");
      //获取每个键值对中的值
      string[] shops = cookie.Values[i].Split(',');
      //获取商品名称
      sb.Append("<td>" + shops[0] + "</td>");
      //获取商品价格
      sb.Append("<td>" + shops[1] + "</td>");
      sb.Append("</td>");
      sb.Append("</tr>");
    }
    sb.Append("</table>");
    mydiv.InnerHtml = sb.ToString();
  }
}

protected void Page_Load(object sender, EventArgs e)
{
  if (!IsPostBack)
  {
    if (!string.IsNullOrEmpty(Request.QueryString["id"]))
    {
      string id = Request.QueryString["id"];
      DeleteShop(id);
    }
  }
}
private void DeleteShop(string id)
{
  if (Request.Cookies["shop"] != null)
  {
    HttpCookie cookie = Request.Cookies["shop"];
    cookie.Values.Remove(id);
    if (cookie.Values.Count == 0)
    {
      cookie.Expires = DateTime.Now.AddDays(-1);
    }
    Response.Cookies.Add(cookie);
    LoadShop();
  }
}