防止重复提交表单

public class RefreshServe : System.Web.UI.Page
    {
        private static ILog log = LogManager.GetLogger(typeof(RefreshServe));
 
        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())
                {
                    log.Debug("刷新了页面");
                    return true;
                }
                else
                {
                    log.Debug("正常提交");
                    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;
        }

 需要刷新判断功能时新页面只需继承该类就可,通过引用属性IsPageRefreshed识别"为真表示刷新,假则是正常提交",将数据库的操作写在

if(!IsPageRefreshed)

{

   数据库操作

}

即可,如果是刷新不会执行,代码中注释部分使用的是Session方式保存票证,因为session比较容易丢失且占内存,所以使用cookie,