第十节 15ASP.Net中使用Cookie 简单

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Cookie1.aspx.cs" Inherits="Cookie1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Button ID="Button1" runat="server" Text="设置Cookie" 
            onclick="Button1_Click" />
    </div>
    
    <a href="Cookie_Read.aspx">点击这里去另外一个页面，读取COOKIE值</a>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
/* COOKIE
 * 表单和页面相关的，只有浏览器端提交了这些数据服务器端才能得到，而有时候希望在服务端任意的地方存取一些和访问者相关的信息，这时候就不方便将这些信息保存到表单中了，因为如果那样的话，必须随时浏览在所有页面表单中都保存这些信息，
 * Cookie是和站点相关的，并且每次向服务器请求的时候都会携带和站点相关的所有cookie,是强制性的，
 * cookie也是保存在浏览器端的，而且浏览器会在每次请求的时候都会把和这个站点的相关的Cookie提交到服徊器，并且将服务端返回的cookie更新回数据库，因为可以将信息保存在Cookie中，然后在服务器端读取，修改
 * 
 * 案例: 一个页面设置Cookie,一个页面读取Cookie
 * 设置的而面,Response.SetCookie(new HttpCookie("UserName",TextBox1.Text))
 * 读取的页面: Label1.Text = Request.Cookies["UserName"].vale;
 * 
 * Cookie的缺点和表单干 样，而且还不能存储过多的信息
 * 
 * 互联网优化的案例:图片服务器和主站域名不一样，降低COOKIE流量的传输
 */
public partial class Cookie1 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        //在客户填也能通过$.cookie取，服务端设置cookie
        Response.SetCookie(new HttpCookie("UserName","小向"));
        Response.SetCookie(new HttpCookie("Uid","1"));
    }
}

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Button ID="Button1" runat="server" Text="点击读取COOKIE值" 
            onclick="Button1_Click" />
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Cookie_Read : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string name = Request.Cookies["UserName"].Value;
        string id = Request.Cookies["Uid"].Value;
        Response.Write("UserName:"+name+", Uid:"+id);

    }
}

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="变量1.aspx.cs" Inherits="变量1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
        <asp:Label ID="Label1" runat="server" Text="0"></asp:Label>
        <br />
        <br />
        <asp:Button ID="Button2" runat="server" onclick="Button2_Click" 
            Text="设置Session" />
        <asp:Button ID="Button3" runat="server" onclick="Button3_Click" 
            Text="读取Session" />
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class 变量1 : System.Web.UI.Page
{

    private int i = 11;
    //每次请求来了都会new一个新的实现了IHttpHandler接口的类"变量1" 的实例进行处理
    //用完了就回调，所以不会保持上次的值

    private static int j = 11; //所有访问都都访问同一个j的实例
    
    
    
    protected void Page_Load(object sender, EventArgs e)
    {
        //如果取不取MySessionID
        if (Request.Cookies["MySessionId"] == null) 
        {
            string sessionid = Guid.NewGuid().ToString(); //生成一个sessionid
            Response.SetCookie(new HttpCookie("MySessionId", sessionid));
        }

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Response.Write("现在i的值为:"+i.ToString());
        i = i + 1;
        j = j + 1;

        Label1.Text = i.ToString();
        Response.Write("现在i的值为:" + i.ToString());

        Response.Write("现在j的值为:" + j.ToString());
    }

    //设置session
    protected void Button2_Click(object sender, EventArgs e)
    {
        //取得保存在cookie里面的sessionid
        string sessionid = Request.Cookies["MySessionId"].Value;

        
        IDictionary<string, object> session = MySession.GetSession(sessionid);
        //session["服务端的数据"] = "333333";
        //这里需要特别注意，必须在设置session值是让两行在一起，不然就是提示错误
        session["服务端的数据"] = DateTime.Now.ToString();


        
        Response.Write("session值为:" + session["另外一个值是"]);
        session["另外一个值是"] = "666666";
        
        //向和这个客户端关联的服务端内存中添加键值对
        //session["username"] = 20;

    }

    //读取session
    protected void Button3_Click(object sender, EventArgs e)
    {
        string sessionid = Request.Cookies["MySessionId"].Value;
        //ySession mys =  new MySession();
        IDictionary<string, object> session = MySession.GetSession(sessionid);
        //Response.Write("读取的值为:" + session["另外一个值是"]);

        //Convert.ToString(session["服务端的数据"]) 
        Button3.Text = Convert.ToString(session["服务端的数据"]) + session["另外一个值是"];
 

    }
}