Cookie对象
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Cookie对象是HttpCookieCollection类的一个实例，它用于保存客户端浏览器请求的服务器页面，也可以用它存取非敏感性的用户信息，信息保存的时间可以根据需要设置。如果没有设置Cookie失效日期，那么它们仅保存到关闭浏览器程序为止；如果将Cookie对象的Expires属性设置为MinValue，则表示Cookie永远不会过期。Cookie存储的数据量很受限制，大多数浏览器支持的最大容量为4096字节，因此，一般不要用来保存数据集或其他大量数据。由于并非所有的浏览器都支持Cookie，并且数据住处是以明文文本的形式保存在客户端计算机中，因此最好不要保存敏感的、未加密的数据，否则会影响网络的安全性。
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新建一个网站，包括一个网页，代码如下：
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1、Default.aspx代码：
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<%@ Page Language=”C#” AutoEventWireup=”true” CodeFile=”Default.aspx.cs” Inherits=”_Default” %>
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<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
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<html xmlns=”http://www.w3.org/1999/xhtml” >
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<head runat=”server”>
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<title>无标题页</title>
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</head>
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<body>
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<form id=”form1″ runat=”server”>
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<div> 数据加密<br />
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<asp:TextBox ID=”TextBox1″ runat=”server”></asp:TextBox><br />
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<asp:Button ID=”Button2″ runat=”server” Text=”数据加密” onClick=”Button2_Click” /><br />
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保存网站信息<br />
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<asp:TextBox ID=”TextBox2″ runat=”server”></asp:TextBox>
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<asp:Button ID=”Button3″ runat=”server” onClick=”Button3_Click” Text=”写” Height=”20px” Width=”44px” />
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<asp:Button ID=”Button4″ runat=”server” Text=”读” Height=”19px” onClick=”Button4_Click” Width=”58px” />
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<asp:TextBox ID=”TextBox3″ runat=”server”></asp:TextBox> <br />
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<asp:Button ID=”Button1″ runat=”server” onClick=”Button1_Click” Text=”Button” /><br />
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<asp:Label ID=”Label1″ runat=”server” Height=”14px” Text=”Label” Width=”358px”></asp:Label><br />
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<asp:Label ID=”Label2″ runat=”server” Height=”13px” Text=”Label” Width=”358px”></asp:Label><br />
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<asp:Label ID=”Label3″ runat=”server” Height=”9px” Text=”Label” Width=”356px”></asp:Label><br />
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</div>
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</form>
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</body>
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</html>
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Default.aspx.cs代码：
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using System;
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using System.Data;
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using System.Configuration;
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using System.Web;
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using System.Web.Security;
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using System.Web.UI;
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using System.Web.UI.WebControls;
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using System.Web.UI.WebControls.WebParts;
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using System.Web.UI.HtmlControls;
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public partial class _Default : System.Web.UI.Page
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{
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protected void Page_Load(object sender, EventArgs e)
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{
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}
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protected void Button1_Click(object sender, EventArgs e)
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{
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if (Request.Cookies["userInfo"] != null)
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{
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this.Label1.Text = Request.Cookies["userInfo"]["userName"];
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this.Label2.Text = Request.Cookies["userInfo"]["lastVist"];
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}
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HttpCookie aCookie;
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for (int i = 0; i < Request.Cookies.Count; i++)
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{
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aCookie = Request.Cookies[i];
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this.Label3.Text = string.Format(“Cookie 名称={0}<br>Cookie 值={1}”, aCookie.Name, aCookie.Value);
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}
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}
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protected void Button2_Click(object sender, EventArgs e)
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{
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string strPwd = TextBox1.Text;
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Response.Cookies["strPwd"].Value = FormsAuthentication.HashPasswordForStoringInConfigFile(strPwd, “md5″);
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Response.Write(Response.Cookies["strPwd"].Value.ToString());
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}
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protected void Button3_Click(object sender, EventArgs e)
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{
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HttpCookie makecookie = new HttpCookie(“Cookie”);
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makecookie.Value = this.TextBox2.Text;
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Response.Cookies.Add(makecookie);
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}
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protected void Button4_Click(object sender, EventArgs e)
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{
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HttpCookie readcookie = Request.Cookies["cookie"];
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this.TextBox3.Text = readcookie.Value;
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}
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}
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