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,