C# Session的生命周期问题

        /// <summary>
        /// 设置session
        /// </summary>
        /// <param name="name">session 名</param>
        /// <param name="val">session 值</param>
        public static void SetSession(string name, object val)
        {
            HttpContext.Current.Session.Remove(name);
            HttpContext.Current.Session.Add(name, val);
            HttpContext.Current.Session.Timeout = 1440;
        }
        /// <summary>
        /// 添加Session，调动有效期为1440分钟
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValue">Session值</param>
        public static void Add(string strSessionName, string strValue)
        {
            HttpContext.Current.Session[strSessionName] = strValue;
            HttpContext.Current.Session.Timeout = 1440;
        }

        /// <summary>
        /// 添加Session，调动有效期为1440分钟
        /// </summary>
        /// <param name="strSessionName">Session对象名称</param>
        /// <param name="strValues">Session值数组</param>
        public static void Adds(string strSessionName, string[] strValues)
        {
            HttpContext.Current.Session[strSessionName] = strValues;
            HttpContext.Current.Session.Timeout = 1440;
        }