asp.net做购物车

     {
         Response.Redirect("~/User/shopCart.aspx");
     }
}
购物车显示页面代码如下：
<%@ Page Language="C#" MasterPageFile="~/default.master" AutoEventWireup="true" CodeFile="shopCart.aspx.cs" Inherits="User_shopCart" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
     <br />
     <asp:Label ID="labMessage" runat="server"   width="122px"></asp:Label><br />
     总价：<asp:Label ID="labTotalPrice" runat="server" Width="60px"></asp:Label><br />
     <asp:GridView ID="gvShopCart" runat="server" AllowPaging="True" PageSize="4"   Width="635px"   OnRowCommand="gvShopCart_RowCommand" AutoGenerateColumns="False">
         <Columns>
             <asp:BoundField HeaderText="序列号" DataField="No" ReadOnly="True" />
             <asp:BoundField HeaderText="商品名称" DataField="productName" ReadOnly="True" />
             <asp:BoundField HeaderText="单价(元)" DataField="productPrice" ReadOnly="True" />
             <asp:TemplateField HeaderText="数量(件)">
             <ItemTemplate>
                 &nbsp;<asp:TextBox ID="txtNumber" runat="server" Width="40px" Text='<%#Eval("Number") %>'   ></asp:TextBox>
             </ItemTemplate>
             </asp:TemplateField>
            <asp:BoundField HeaderText="商品总价(元)" DataField="totalPrice" ReadOnly="True" />
              <asp:TemplateField HeaderText="删除" >
               <ItemTemplate>
               <asp:LinkButton ID="lnkdel" runat="server" Text="删除" CommandName="del" CommandArgument='<%#Eval("ID") %>'></asp:LinkButton>
               </ItemTemplate>
             </asp:TemplateField>
         </Columns>


     </asp:GridView>
     <asp:LinkButton ID="lnkbtnUpdate" runat="server" OnClick="lnkbtnUpdate_Click" Font-Size="X-Large">更新购物车</asp:LinkButton>
     <asp:LinkButton ID="lnkbtnClear" runat="server" OnClick="lnkbtnClear_Click" Font-Size="X-Large">清空购物车</asp:LinkButton>
     <asp:LinkButton ID="lnkbtnContinue" runat="server" OnClick="lnkbtnContinue_Click" Font-Size="X-Large">继续购物</asp:LinkButton><br />
购物车后面的cs页面代码如下：
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 User_shopCart : System.Web.UI.Page
{
     string strSql;
     DataTable dtTable;
     Hashtable hashCar;
     protected void Page_Load(object sender, EventArgs e)
     {
         if (!IsPostBack)
         {
             cj();
         }           
     }
     private void cj()
     {
         if (Session["ShopCart"] == null)
         {
             this.labMessage.Text = "您还没有购物！";
             this.labMessage.Visible = true;
             this.lnkbtnClear.Visible = false;
             this.lnkbtnContinue.Visible = false;
         }
         else
         {
             hashCar = (Hashtable)Session["ShopCart"];
             if (hashCar.Count == 0)
             {
                 this.labMessage.Text = "您购物车中的没有商品!";
                 this.labMessage.Visible = true;
                 this.lnkbtnClear.Visible = false;


                 this.lnkbtnContinue.Visible = false;
             }
             else
             {
                 dtTable = new DataTable();
                 DataColumn column1 = new DataColumn("No");
                 DataColumn column2 = new DataColumn("ID");
                 DataColumn column3 = new DataColumn("productName");
                 DataColumn column4 = new DataColumn("productPrice");
                 DataColumn column5 = new DataColumn("Number");
                 DataColumn column6 = new DataColumn("totalPrice");
                 dtTable.Columns.Add(column1);
                 dtTable.Columns.Add(column2);
                 dtTable.Columns.Add(column3);
                 dtTable.Columns.Add(column4);
                 dtTable.Columns.Add(column5);
                 dtTable.Columns.Add(column6);
                 DataRow row;
                 foreach (object key in hashCar.Keys)
                 {
                     row = dtTable.NewRow();
                     row["ID"] = key.ToString();
                     row["Number"] = hashCar[key].ToString();
                     dtTable.Rows.Add(row);


                 }
                 DataTable dstable;
                 int i = 1;
                 float price;
                 int count;
                 float totalPrice = 0;
                 foreach (DataRow drRow in dtTable.Rows)
                 {
                     strSql = "select productName,productPrice from product where ID=" + Convert.ToInt32(drRow["ID"].ToString());
                     dstable = DbManager.ExecuteQuery(strSql);
                     drRow["No"] = i;
                     drRow["productName"] = dstable.Rows[0].ItemArray[0].ToString();
                     drRow["productPrice"] = (dstable.Rows[0].ItemArray[1].ToString());
                     price = float.Parse(dstable.Rows[0].ItemArray[1].ToString());
                     count = Int32.Parse(drRow["Number"].ToString());
                     drRow["totalPrice"] = price * count;
                     totalPrice += price * count;
                     i++;
                 }
                 this.labTotalPrice.Text = totalPrice.ToString();
                 this.gvShopCart.DataSource = dtTable.DefaultView;
                 this.gvShopCart.DataKeyNames = new string[] { "ID" };


                 this.gvShopCart.DataBind();
             }
         }
     }
protected void lnkbtnUpdate_Click(object sender, EventArgs e)
     {
         hashCar = (Hashtable)Session["ShopCart"];
         foreach (GridViewRow gvr in this.gvShopCart.Rows)
         {
             TextBox otb = (TextBox)gvr.FindControl("txtNumber");
             int count = Int32.Parse(otb.Text);
             string ID = gvr.Cells[1].Text;
             hashCar[ID] = count;
         }
         Session["ShopCart"] = hashCar;
         Response.Write("<script>alert('更新成功!')</script>");
     }
     protected void lnkbtnClear_Click(object sender, EventArgs e)
     {
         Session["ShopCart"] = null;
         Response.Redirect("ShoppCart.aspx");
     }
     protected void lnkbtnContinue_Click(object sender, EventArgs e)
     {
         Response.Redirect("~/Product/ProNew.aspx");
     }
     protected void gvShopCart_RowCommand(object sender, GridViewCommandEventArgs e)
     {
         if (e.CommandName.Equals("del"))
         {
             hashCar = (Hashtable)Session["ShopCart"];
             hashCar.Remove(e.CommandArgument);
             Session["ShopCart"] = hashCar;
             Response.Redirect("ShopCart.aspx");
         }
     }
   
}
下图是购物车页面中显示的：修改商品的数量后，我击一下“更新购物车”跟在后面的商品总价和最上面的总价都怎么不改变，求高手帮忙，应该怎样做



更新购物车的LinkButton的ID为lnkbtnUpdate

看的蛋疼

foreach (GridViewRow gvr in this.gvShopCart.Rows)
{
TextBox otb = (TextBox)gvr.FindControl("txtNumber");
int count = Int32.Parse(otb.Text);
string ID = gvr.Cells[1].Text;
hashCar[ID] = count;
}
Session["ShopCart"] = hashCar;
感觉这段逻辑有些问题,不太清楚你hashCar中的结构,但感觉直接把数量赋值给hashCar中的商品名称有点不太对劲I