在网站中使用Cookie的简单例子

前台放一个TextBox、一个Label、一个Button（value="注销"）

后台：

using System;
using System.Data;
using System.Configuration;
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 _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string name = this.TextBox1.Text;

        HttpCookie coolie = new HttpCookie("UserName");

        coolie.Value = name;
        coolie.Expires = DateTime.Now.AddDays(7);

        this.Response.Cookies.Add(coolie);
    }
    protected void LinkButton1_Click(object sender, EventArgs e)
    {
        //检查请求中的Cookie信息
        HttpCookie cookie = this.Request.Cookies["UserName"];
        if (cookie != null)
        {
            this.Label1.Text = string.Format("你的名字是:{0}", cookie.Value);
        }
        else
        {
            this.Label1.Text = "未知用户";
        }
    }
    protected void LinkButton2_Click(object sender, EventArgs e)
    {
        //通过创建Expires的过期时间来达到删除的目的
        HttpCookie cookie = new HttpCookie("UserName");

        cookie.Expires = new DateTime(1999, 1, 1);

        this.Response.Cookies.Add(cookie);
    }
}