Cookie用法

//Cookie写操作--------------------------------
        Response.Cookies["userName"].Value = "patrick";
        Response.Cookies["userName"].Expires = DateTime.Now.AddDays(1);

        HttpCookie aCookie = new HttpCookie("newName");
        aCookie.Value = DateTime.Now.ToString();
        aCookie.Expires = DateTime.Now.AddDays(1);
        Response.Cookies.Add(aCookie);
        //Cookie读操作--------------------------
        if (Request.Cookies["userName"] != null)
            Label1.Text = Server.HtmlEncode(Request.Cookies["userName"].Value);

        if (Request.Cookies["userName"] != null)
        {
            HttpCookie aCookie = Request.Cookies["userName"];
            Label1.Text = Server.HtmlEncode(aCookie.Value);
        }
        //Cookie删操作---------------------------------
        HttpCookie aCookie;
        string cookieName;
        int limit = Request.Cookies.Count;
        for (int i = 0; i < limit; i++)
        {
            cookieName = Request.Cookies[i].Name;
            aCookie = new HttpCookie(cookieName);
            aCookie.Expires = DateTime.Now.AddDays(-1);
            Response.Cookies.Add(aCookie);
        }

        //多值Cookie-----------------------------------------