Asp.Net ：写入 、读取 、 删除、追加cookie数组?

//-----------------------------载入
if(!IsPostBack)
        {

            HttpCookie cookie = Request.Cookies["userinfo1"];
            cookie.Expires = System.DateTime.Now.AddMinutes(20);//设置过期时间
            for (int i = 0; i < 5; i++)
            {
                cookie.Values["BB" + i.ToString()] = i.ToString();
                Response.Cookies.Add(cookie);
            }
           
   }



//**************写入
       HttpCookie cookie = new HttpCookie("userinfo1");
        cookie.Expires = System.DateTime.Now.AddMinutes(20);//设置过期时间
        for (int i = 0; i < 10; i++)
        {
           
            cookie.Values["U" +i.ToString()] = i.ToString();          
            Response.Cookies.Add(cookie);
        }


//**************---------------读取
        //读取 Cookie 集合
        for (int i = 0; i < Request.Cookies.Count; i++)
        {
            if (Request.Cookies.AllKeys[i] == "userinfo1")
            {

                HttpCookie cookies = Request.Cookies["userInfo1"];
                Response.Write("name=" + cookies.Name + "<br/>");
                //Response.Write("name=" + cookies.Value + "<br/>");

                if (cookies.HasKeys)//是否有子键
                {
                    System.Collections.Specialized.NameValueCollection NameColl = cookies.Values;
                    for (int j = 0; j < NameColl.Count; j++)
                    {
                       
                        Response.Write("子键名=" + NameColl.AllKeys[j] + "<br/>");
                        Response.Write("子键值=" + NameColl[j] + "<br/>");
                    }

                }
                else
                {
                    Response.Write("value=" + cookies.Value + "<br/>");
                }
            }
         
        }


//***********************删除
HttpCookie acookie = Request.Cookies["userinfo1"];
        acookie.Expires = System.DateTime.Now.AddMinutes(20);//设置过期时间      
        if (acookie.HasKeys)//是否有子键
        {
            System.Collections.Specialized.NameValueCollection NameColl = acookie.Values; 
            for (int j = 0 ; j < NameColl.Count; j++)
            {               
                if (NameColl.AllKeys[j] == "U8")
                {
                    acookie.Values.Remove(NameColl.AllKeys[j]);
                    Response.Cookies.Add(acookie);
                }              
            }   
        }


//***************************追加
 HttpCookie cookie = Request.Cookies["userinfo1"];
        cookie.Expires = System.DateTime.Now.AddMinutes(20);//设置过期时间
        for (int i = 0; i < 5; i++)
        {
            cookie.Values["K" + i.ToString()] = i.ToString();
            Response.Cookies.Add(cookie);
        }