Response.AppendCookie

//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);
        }
    }