c#利用Session对象实现购物车的方法示例

//shopcart.aspx.cs

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;
using System.Data.SqlClient;
using System.Text.RegularExpressions; 

public partial class shopCart : System.Web.UI.Page
{
  CommonClass ccObj = new CommonClass();
  DBClass dbObj = new DBClass();
  string strSql;
  DataTable dtTable;
  Hashtable hashCar;
  protected void Page_Load(object sender, EventArgs e)
  {
    if (!IsPostBack)
    {
      if (Session["ShopCart"] == null)
      {
        //如果没有购物，则给出相应信息，并隐藏按钮
        this.labMessage.Text = "您还没有购物！";
        this.labMessage.Visible = true;    //显示提示信息
        this.lnkbtnCheck.Visible = false;   //隐藏“前往服务台”按钮
        this.lnkbtnClear.Visible = false;   //隐藏“清空购物车”按钮
        this.lnkbtnContinue.Visible = false;  //隐藏“继续购物”按钮

      }
      else
      {
        hashCar = (Hashtable)Session["ShopCart"]; //获取其购物车
        if (hashCar.Count == 0)
        {
          //如果没有购物，则给出相应信息，并隐藏按钮
          this.labMessage.Text = "您购物车中没有商品！";
          this.labMessage.Visible = true;    //显示提示信息
          this.lnkbtnCheck.Visible = false;   //隐藏“前往服务台”按钮
          this.lnkbtnClear.Visible = false;   //隐藏“清空购物车”按钮
          this.lnkbtnContinue.Visible = false;  //隐藏“继续购物”按钮

        }
        else
        {
          //设置购物车内容的数据源
          dtTable = new DataTable();
          DataColumn column1 = new DataColumn("No");    //序号列
          DataColumn column2 = new DataColumn("BookID");  //书籍ID代号
          DataColumn column3 = new DataColumn("BookName"); //书籍名称
          DataColumn column4 = new DataColumn("Num");    //数量
          DataColumn column5 = new DataColumn("price");   //单价
          DataColumn column6 = new DataColumn("totalPrice");//总价
          dtTable.Columns.Add(column1); //添加新列      
          dtTable.Columns.Add(column2);
          dtTable.Columns.Add(column3);
          dtTable.Columns.Add(column4);
          dtTable.Columns.Add(column5);
          dtTable.Columns.Add(column6);
          DataRow row;
          //对数据表中每一行进行遍历，给每一行的新列赋值
          //foreach (object key in hashCar.Keys)
          //{
          //  row = dtTable.NewRow();
          //  row["BookID"] = key.ToString();
          //  row["Num"] = hashCar[key].ToString();
          //  dtTable.Rows.Add(row);
          /