congo.aspx和congo.cs和ViewCart.aspx

ShoppingCart 是Congo.cs中定义的一种自定义数据类型。它还伴随着BookOrder，也是在Congo.cs中定义。
ShoppingCart主要是对HashTable的包装。
它实现了一个名为_Orders的私有字段，该字段持有一个HashTable引用，ShoppingCart 还实现了一些公有方法，这些方法使BookOrder对象能够被添加到HashTable中并被删除，
ShoppingCart还实现了一个名为Orders的公共属性，该属性在HashTable的ICollection接口中可用：
aspx：

congo.aspx.cs:

using System;

using System.Data;

using System.Data.SqlClient;

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 congo : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

string ConnectString = ConfigurationSettings.AppSettings["connectString"];

SqlDataAdapter adapter = new SqlDataAdapter("select * from titles where price!=0", ConnectString);

DataSet ds = new DataSet();

adapter.Fill(ds);

MyDataGrid.DataSource = ds;

MyDataGrid.DataBind();

}

//用户调用该页面并单击“AddToCart”按钮时调用该方法

/// <summary>

/// 该方法从DataGrid中检索产品ID及相应书籍的价格，并将

/// 它们封装到一个BookOrder对象中

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

protected void OnItemCommand(Object sender, DataGridCommandEventArgs e)

{

if (e.CommandName == "AddToCart")

{

//有两种方法可以得到这里的BookOrder、ShoppingCart

//1.把congo.cs放在App_Code文件夹内。

//2.把congo.cs编译成dll文件放在Bin文件夹内

//倾向于前者，便于查看Congo.cs的内容

BookOrder order =

new BookOrder(e.Item.Cells[0].Text,e.Item.Cells[1].Text,Convert.ToDecimal(e.Item.Cells[2].Text.Substring(1)),1);

//global.asax中有Session_Start,这里的SessionID？？？？

ShoppingCart cart = (ShoppingCart)Session["MyShoppingCart"];

if (cart != null)

{

cart.AddOrder(order);

}

Response.Write("<script>alert('success to add "+e.Item.Cells[1].Text+"')</script>");

}

protected void OnViewCart(Object sender, EventArgs e)

{

Response.Redirect("ViewCart.aspx");

}

global.asax:

<%@ Application Language="C#" %>

void Application_Start(object sender, EventArgs e)

{

// Code that runs on application startup

}

void Application_End(object sender, EventArgs e)

{

// Code that runs on application shutdown

}

void Application_Error(object sender, EventArgs e)

{

// Code that runs when an unhandled error occurs

}

void Session_Start(object sender, EventArgs e)

{

//为请求页面的用户创建一个会话

Session["MyShoppingCart"] = new ShoppingCart();

// Code that runs when a new session is started

}

void Session_End(object sender, EventArgs e)

{

// Code that runs when a session ends.

// Note: The Session_End event is raised only when the sessionstate mode

// is set to InProc in the Web.config file. If session mode is set to StateServer

// or SQLServer, the event is not raised.

}

</script>

congo.cs(独立代码，在App_Code)中

ViewCart.aspx和aspx.cs:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ViewCart.aspx.cs" Inherits="ViewCart" %>
2

<html xmlns="http://www.w3.org/1999/xhtml" >
5

<head runat="server">
6

<title>Untitled Page</title>
7

</head>
8

<body>
9

<form id="form1" runat="server">
10

<div>
11

<table width="100%" bgcolor="teal">
12

<tr>
13

<td>
14

<asp:Button ID="lblReturnShop" Text="Return to Shopping" OnClick="OnShop" runat="server" />
15

</td>
17

</tr>
18

</table>
19

</div>
20

<br />
22

<center>
23

<asp:DataGrid ID="MyDataGrid" AutoGenerateColumns="false" CellPadding="2"
24

BorderWidth="1" BorderColor="lightgray" Font-Names="Verdana"
25

Font-Size="8pt" GridLines="vertical" Width="90%" OnItemCommand="OnItemCommand" runat="server">
26

<Columns>
27

<asp:BoundColumn HeaderText="Item ID" DataField="ItemID">
28

</asp:BoundColumn>
29

<asp:BoundColumn HeaderText="Title" DataField="Title">
31

</asp:BoundColumn>
32

<asp:BoundColumn HeaderText="Price" DataField="Price" DataFormatString="{0:C}"
33

HeaderStyle-HorizontalAlign="center" ItemStyle-HorizontalAlign="right">
34

</asp:BoundColumn>
35

<asp:BoundColumn HeaderText="Quantity" DataField="Quantity"
37

HeaderStyle-HorizontalAlign="center" ItemStyle-HorizontalAlign="center">
38

</asp:BoundColumn>
39

<asp:ButtonColumn HeaderText="Action" Text="Remove"
40

HeaderStyle-HorizontalAlign="center" ItemStyle-HorizontalAlign="center" CommandName="RemoveFromCart">
41

</asp:ButtonColumn>
42

</Columns>
43

<HeaderStyle BackColor="teal" ForeColor="white" Font-Bold="true" />
45

<ItemStyle BackColor="white" ForeColor="darkblue" />
46

<AlternatingItemStyle BackColor="beige" ForeColor="darkBlue" />
47

</asp:DataGrid>
48

</center>
49

<h3><asp:Label ID="Total" runat="server"></asp:Label></h3>
50

</form>
51

</body>
52

</html>
53

ViewCart.aspx.cs:

viewCart.cs