.net防止重复提交

  /**防止刷新页面导致重复提交页面 **/

该部分放入到公共类中  方便单个页面的使用
        private readonly string REFRESH_TICKET_NAME = "__RefreshTicketArray";
        private readonly string HIDDEN_FIELD_NAME = "__RefreshHiddenField";
        private readonly string HIDDEN_PAGE_GUID = "__RefreshPageGuid";

        /// <summary>
        /// 为True表示页面刷新,False为正常提交
        /// </summary>
        public bool IsPageRefreshed
        {
            get
            {
                if (IsPostBack && !CheckRefreshFlag())
                {
                
                    return true;
                }
                else
                {
              
                    return false;
                }
            }
        }

        /// <summary>
        /// 呈现前更新标识
        /// </summary>
        /// <param name="e"></param>
        protected override void OnPreRender(EventArgs e)
        {
            // log.Debug("执行OnPreRender");
            base.OnPreRender(e);
            UpdateRefreshFlag();
        }


        /// <summary>
        /// 更新标识,正常提交都删除该次提交的时间,并生产当前新的时间
        /// </summary>
        private void UpdateRefreshFlag()
        {

            #region Cookie模式

            //注册页面唯一标识并返回
            string pageGuid = SetCurPageGuid();

            HttpCookie cookie = GetRefreshTicket();

            if (cookie.Values.Count > 0)
            {
                cookie.Values.Remove(pageGuid);
                //   log.Debug("当前清除的cookie变是:" + pageGuid);
            }

            string submitTime = DateTime.Now.ToString("hhmmss.fffff");
            //当前提交时间保存到隐藏域
            ClientScript.RegisterHiddenField(HIDDEN_FIELD_NAME, submitTime);


            // log.Debug("即将要新增的时间:submitTime:" + submitTime + "  Guid:" + pageGuid.ToString());
            cookie.Values.Add(pageGuid, submitTime);

            //  log.Debug("UpdateRefreshFlag中当前Cookie中存在的记录数为:" + cookie.Values.Count);
            //  for (int i = 0; i < cookie.Values.Count; i++)
            // log.Info("cookie[" + cookie.Values.GetKey(i) + "]:" + cookie.Values[i]);

            Response.AppendCookie(cookie);

            #endregion

        }


        /// <summary>
        /// 验证是否刷新
        /// </summary>
        /// <returns></returns>
        private bool CheckRefreshFlag()
        {
            HttpCookie cookie = GetRefreshTicket();
            string pageGuid = GetCurPageGuid();
            if (cookie.Values.Count > 0)
            {
                bool flag;
                if (cookie.Values[pageGuid] != null)
                    flag = cookie.Values[pageGuid].IndexOf(GetCurSubmitTime()) > -1;
                else
                    flag = true;//防止出现异常,总是可以提交
                // if (flag)
                //   log.Debug("提交时间存在,可以提交");
                //  else
                // log.Debug("无效的提交时间");
                return flag;
            }
            return true;
        }


        /// <summary>
        /// 得到已保存的提交时间,没有新建,有返回
        /// </summary>
        /// <returns></returns>
        private HttpCookie GetRefreshTicket()
        {
            #region Cookie模式,返回值为Cookie

            HttpCookie cookie;
            if (Request.Cookies[REFRESH_TICKET_NAME] == null)
            {
                cookie = new HttpCookie(REFRESH_TICKET_NAME);
                Response.AppendCookie(cookie);
                //  log.Debug("Cookie不存在，初始化");
            }
            else
            {
                cookie = Request.Cookies[REFRESH_TICKET_NAME];

                //  log.Debug("读取已存在的Cookie,当前Cookie中存在的记录数为:" + cookie.Values.Count + "具体有如下几条:");

                // for (int i = 0; i < cookie.Values.Count; i++)
                // log.Info("cookie[" + cookie.Values.GetKey(i) + "]:" + cookie.Values[i]);
            }
            return cookie;
            #endregion
        }


        /// <summary>
        /// 获取当前提交时间
        /// </summary>
        /// <returns></returns>
        private string GetCurSubmitTime()
        {
            string submitTime = Request.Params[HIDDEN_FIELD_NAME] == null ? "" : Request.Params[HIDDEN_FIELD_NAME].ToString();
            //  log.Debug("执行GetCurSubmitTime:submitTime为:" + submitTime);
            return submitTime;
        }


        /// <summary>
        /// 设置页面唯一标识,通过Guid标识来区分每个页面自己的提交时间
        /// </summary>
        private string SetCurPageGuid()
        {
            string guid;
            if (!IsPostBack)
            {
                if (Request.Params[HIDDEN_PAGE_GUID] == null)
                {
                    guid = System.Guid.NewGuid().ToString();
                    //  log.Debug("SetCurPageGuid注册了一个新的标识:" + guid);
                }
                else
                    guid = GetCurPageGuid();

            }
            else
            {
                guid = GetCurPageGuid();
            }

            ClientScript.RegisterHiddenField(HIDDEN_PAGE_GUID, guid);
            return guid;
        }



        /// <summary>
        /// 得到当前页面的唯一标识
        /// </summary>
        /// <returns></returns>
        private string GetCurPageGuid()
        {
            string pageGuid = Request.Params[HIDDEN_PAGE_GUID] == null ? "none" : Request.Params[HIDDEN_PAGE_GUID].ToString();
            // log.Debug("执行GetCurPageGuid()后Page_GUID为:" + pageGuid);
            return pageGuid;
        }
/*/**/在防止重复提交的事件中使用

if (!IsPageRefreshed)
            {

}

else

{

 // 重复提交

}