//写入    protected void Button2_Click(object sender, EventArgs e)    {        HttpCookie cookie=new HttpCookie("MyCook");//初使化并设置Cookie的名称        DateTime dt=DateTime.Now;        TimeSpan ts = new TimeSpan(0, 0, 1,0,0);//过期时间为1分钟        cookie.Expires = dt.Add(ts);//设置过期时间        cookie.Values.Add("userid", "userid_value");        cookie.Values.Add("userid2","userid2_value2");        Response.AppendCookie(cookie);        //输出该Cookie的所有内容        //Response.Write(cookie.Value); //输出为：userid=userid_value&userid2=userid2_value2     }    //读取    protected void Button1_Click(object sender, EventArgs e)    {       // HttpCookie cokie = new HttpCookie("MyCook");//初使化        if (Request.Cookies["MyCook"]!=null)        {            //Response.Write("Cookie中键值为userid的值:" + Request.Cookies["MyCook"]["userid"]);//整行            //Response.Write("Cookie中键值为userid2的值" + Request.Cookies["MyCook"]["userid2"]);            Response.Write(Request.Cookies["MyCook"].Value);//输出全部的值        }    }    //修改Cookie    protected void Button3_Click(object sender, EventArgs e)    {        //获取客户端的Cookie对象        HttpCookie cok = Request.Cookies["MyCook"];                if (cok != null)        {         //修改Cookie的两种方法            cok.Values["userid"] = "alter-value";            cok.Values.Set("userid", "alter-value");          //往Cookie里加入新的内容             cok.Values.Set("newid", "newValue");             Response.AppendCookie(cok);        }          }    //删除Cookie    protected void Button4_Click(object sender, EventArgs e)    {        HttpCookie cok = Request.Cookies["MyCook"];        if (cok != null)        {            if (!CheckBox1.Checked)            {                cok.Values.Remove("userid");//移除键值为userid的值            }            else            {                TimeSpan ts = new TimeSpan(-1, 0, 0, 0);                cok.Expires = DateTime.Now.Add(ts);//删除整个Cookie，只要把过期时间设置为现在            }            Response.AppendCookie(cok);        }    }