?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 BookTable : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridView1.DataSource = Session["ShoppingCart2"];
            DataBind();
        }
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        double sum = 0.0;
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            sum = sum + (double.Parse(GridView1.Rows[i].Cells[4].Text));
        }
        Label1.Text = sum.ToString() + "元";
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        GridView1.DataSource = Session[""];
        DataBind();
        Label1.Text = "";
    }
}