webform之session传值（临时数据的存储）与扩展属性 --（购物车练习）
页面传值：
1.QueryString传值
在源页面写：Response.Redirect("Main.aspx?uid="+uid+"&pwd="+pwd);
在目标页面：Request["uid"].ToString();
2.Session *****
特点：可以存任何东西，每个用户都会生成一个特定的Session，Session是存储在服务中的，
一般默认存储20分钟，20分钟之后过期
用法：在登录页面：Session["uid"] = uid;
在使用页面：Session["uid"].ToString();
3.Cookie *****
特点：默认永不过期，可以设置它的过期时间，Cookie是存储在客户端的
用法：在登录界面： //新建Cookie对象
HttpCookie cookie_name = new HttpCookie("uid");
//赋值
cookie_name.Value = uid;
//写入到Cookie里面
Response.AppendCookie(cookie_name);
在使用界面：Request.Cookies["uid"].Value.ToString();
4.Application
特点：它是共有的
用法：在源页面： Application["uid"] = uid;
在目标页面： Application.Lock();
Label1.Text = Application["uid"].ToString();
Application.UnLock();
例题 购物车：
目标 ：如何用session与list集合的转换 从何搭建一个临时的数据库表
1、浏览商品界面
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Main.aspx.cs" Inherits="Main" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>大苹果购物网</h1>
<p> </p>
<div style="float:left; width:150px; height:500px;">
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click">浏览商品</asp:LinkButton>
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton2" runat="server" OnClick="LinkButton2_Click">查看账户</asp:LinkButton>
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton3" runat="server" OnClick="LinkButton3_Click">查看购物车</asp:LinkButton>
</div>
<div style =" float:left; height:500px;">
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<table width="600" border="0" cellspacing="1" cellpadding="0" bgcolor="#6600FF">
<tr>
<td height="25" bgcolor="#FFFFFF">代号</td>
<td bgcolor="#FFFFFF">水果名称</td>
<td bgcolor="#FFFFFF">水果价格</td>
<td bgcolor="#FFFFFF">源产地</td>
<td bgcolor="#FFFFFF">库存</td>
<td bgcolor="#FFFFFF">操作</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td height="25" bgcolor="#FFFFFF"><%#Eval("Ids") %></td>
<td bgcolor="#FFFFFF"><%#Eval("Name") %></td>
<td bgcolor="#FFFFFF"><%#Eval("Price") %></td>
<td bgcolor="#FFFFFF"><%#Eval("Source") %></td>
<td bgcolor="#FFFFFF"><%#Eval("Numbers") %></td>
<td bgcolor="#FFFFFF"><a href="ChuLi.aspx?code=<%#Eval("Ids") %>">购买</a></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
<br />
<br />
<asp:Label ID="lblTs" runat="server"></asp:Label>
</div>
cs代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class Main : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Session["uid"] != null)
{
FirutDataContext context = new FirutDataContext();
Repeater1.DataSource = context.Fruit;
Repeater1.DataBind();
if (Session["Cart"] != null)
{
List<OrderDetails> list = Session["Cart"] as List<OrderDetails>;
int sl = list.Count();
decimal zj = Convert.ToDecimal( list.Sum(p => p.Count * p.JiaGe));
lblTs.Text = "购物车中有："+sl+"件商品，总价为："+zj+"元。";
}
}
else
{
Response.Redirect("DengLu.aspx");
}
}
}
protected void LinkButton1_Click(object sender, EventArgs e)
{
Response.Redirect("Main.aspx");
}
protected void LinkButton2_Click(object sender, EventArgs e)
{
Response.Redirect("YuE.aspx");
}
protected void LinkButton3_Click(object sender, EventArgs e)
{
Response.Redirect("GouWuChe.aspx");
}
}
2、点击购买界面：
aspx代码没有东西。
cs代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class ChuLi : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string code = Request["code"].ToString();
if (Session["Cart"] != null)
{
List<OrderDetails> listall = Session["Cart"] as List<OrderDetails>;
var query = listall.Where(p => p.FruitCode == code);
if (query.Count() > 0)
{
OrderDetails data1 = query.First();
//listall.Remove(data1);
data1.Count = data1.Count + 1;
//listall.Add(data1);
Session["Cart"] = listall;
}
else
{
OrderDetails data2 = new OrderDetails();
data2.FruitCode = code;
data2.Count = 1;
listall.Add(data2);
Session["Cart"] = listall;
}
}
else
{
FirutDataContext context = new FirutDataContext();
List<OrderDetails> list = new List<OrderDetails>();
OrderDetails data = new OrderDetails();
data.FruitCode = code;
data.Count = 1;
list.Add(data);
Session["Cart"] = list;
}
Response.Redirect("Main.aspx");
}
}
3、浏览购物车界面
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GouWuChe.aspx.cs" Inherits="GouWuChe" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>购物车</h1>
<p> </p>
<div style="float:left; width:150px; height:500px;">
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click">浏览商品</asp:LinkButton>
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton2" runat="server" OnClick="LinkButton2_Click">查看账户</asp:LinkButton>
<br />
<br />
<br />
<asp:LinkButton ID="LinkButton3" runat="server" OnClick="LinkButton3_Click">查看购物车</asp:LinkButton>
</div>
<div style =" float:left; height:500px;">
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<table width="600" border="0" cellspacing="1" cellpadding="0" bgcolor="#6600FF">
<tr>
<td height="25" bgcolor="#FFFFFF">商品名称</td>
<td bgcolor="#FFFFFF">商品单价</td>
<td bgcolor="#FFFFFF">购买数量</td>
<td bgcolor="#FFFFFF">操作</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td height="25" bgcolor="#FFFFFF"><%#Eval("ShangPinName") %></td>
<td bgcolor="#FFFFFF"><%#Eval("JiaGe") %></td>
<td bgcolor="#FFFFFF"><%#Eval("Count") %></td>
<td bgcolor="#FFFFFF"><a href="ShanChu.aspx?code=<%#Eval("FruitCode") %>">删除</a></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
<br />
<br />
<asp:Label ID="lblTs" runat="server" ForeColor="#CC0000"></asp:Label>
<br />
<br />
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="提交订单" />
<br />
<br />
<asp:Label ID="lblSure" runat="server" ForeColor="#CC0000"></asp:Label>
<br />
</div>
</div>
</form>
</body>
</html>
cs代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class GouWuChe : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Session["Cart"] != null)
{
List<OrderDetails> list = Session["Cart"] as List<OrderDetails>;
Repeater1.DataSource = list;
Repeater1.DataBind();
}
else
{
lblTs.Text = "购物车中没有任何商品！";
}
}
}
protected void LinkButton1_Click(object sender, EventArgs e)
{
Response.Redirect("Main.aspx");
}
protected void LinkButton2_Click(object sender, EventArgs e)
{
Response.Redirect("YuE.aspx");
}
protected void LinkButton3_Click(object sender, EventArgs e)
{
Response.Redirect("GouWuChe.aspx");
}
protected void Button1_Click(object sender, EventArgs e)
{
List<OrderDetails> list = Session["Cart"] as List<OrderDetails>;
FirutDataContext context = new FirutDataContext();
bool IsOk = true;
foreach (OrderDetails data in list)
{
int sl = data.Count.Value;
var query = context.Fruit.Where(p=>p.Ids == data.FruitCode);
int kc = query.First().Numbers.Value;
if (sl <= kc)
{
IsOk = IsOk && true;
}
else
{
IsOk = IsOk && false;
lblSure.Text += query.First().Name +"的库存不足！ ";
}
}
if (IsOk)
{
if (Session["uid"] != null)
{
string uid = Session["uid"].ToString();
var query = context.Login.Where(p=>p.UserName == uid);
decimal ye = query.First().Account.Value;
decimal zj = list.Sum(p => p.JiaGe * p.Count).Value;
if (ye >= zj)
{
//减库存
foreach (OrderDetails data in list)
{
int sl = data.Count.Value;
var query2 = context.Fruit.Where(p => p.Ids == data.FruitCode);
query2.First().Numbers = query2.First().Numbers.Value - data.Count;
context.SubmitChanges();
}
//减余额
var query3 = context.Login.Where(p=>p.UserName == uid);
query3.First().Account = query3.First().Account.Value - zj;
context.SubmitChanges();
//添加订单
Orders data1 = new Orders();
Random r = new Random();
string ordercode = DateTime.Now.ToString("yyyyMMddHHmmssms") + r.Next(100).ToString();
data1.Code = ordercode;
data1.UserName = uid;
data1.OrderTime = DateTime.Now;
context.Orders.InsertOnSubmit(data1);
context.SubmitChanges();
//添加订单详情表
foreach (OrderDetails data in list)
{
data.OrderCode = ordercode;
}
context.OrderDetails.InsertAllOnSubmit(list);
context.SubmitChanges();
}
else
{
lblSure.Text +="余额不足！";
}
}
else
{
Response.Redirect("DengLu.aspx");
}
}
}
}
4、购物车 中 点击 删除 ，操作界面
cs代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class ShanChu : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
List<OrderDetails> list = Session["Cart"] as List<OrderDetails>;
string code = Request["code"].ToString();
var query = list.Where(p => p.FruitCode == code);
if (query.First().Count.Value > 1)
{
query.First().Count--;
}
else
{
list.Remove(query.First());
}
Session["Cart"] = list;
Response.Redirect("GouWuChe.aspx");
}
}
5、查看 账户 界面（无）
6、扩展 orderdetails属性（李老师版本）
public partial class OrderDetails
{
private decimal jiaGe;
public decimal JiaGe
{
get
{
FirutDataContext context = new FirutDataContext();
var query = context.Fruit.Where(p=>p.Ids == FruitCode);
Fruit data = query.First();
return data.Price.Value;
}
set { jiaGe = value; }
}
private string shangPinName;
public string ShangPinName
{
get {
FirutDataContext context = new FirutDataContext();
var query = context.Fruit.Where(p => p.Ids == FruitCode);
Fruit data = query.First();
return data.Name;
}
set { shangPinName = value; }
}
另一版本
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
/// <summary>
/// OrderDetailsBF 的摘要说明
/// </summary>
public partial class OrderDetails
{
private DataClassesDataContext _Context = new DataClassesDataContext();
public string FruitName
{
//相关子查询，用订单表里水果编号查询水果表里水果的名字
get
{
var query = _Context.Fruit.Where(p => p.Ids == this.FruitCode);
if (query.Count() > 0)
{
return query.First().Name;
}
return "";
}
}
public decimal FruitPrice
{
get
{
var query = _Context.Fruit.Where(p => p.Ids == this._FruitCode);
if (query.Count() > 0)
{
return query.First().Price.Value;
}
return 0;
}
}
public List<OrderDetails> Select()
{
return _Context.OrderDetails.ToList();
}
}
如两个表 有直接相关的外键关系（例如nation 表与 info 表中的nation 属性 ）
public partial class Info
{
public string Nname
{
get
{
return this.Nation1.Name;
}
}
}
如果session在一般处理程序集中为null，需要引用using System.Web.SessionState;
