防止刷新提交页面！

 方法一：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public class BasePage : System.Web.UI.Page
{
    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)
    {
        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);
        }

        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);

        cookie.Values.Add(pageGuid, submitTime);

        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
            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);
        }
        else
        {
            cookie = Request.Cookies[REFRESH_TICKET_NAME];
        }
        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();
        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();
            }
            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();
        return pageGuid;
    }
}

 方法二：

 

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Collections;
public class BasePage : System.Web.UI.Page
{
    public BasePage()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    #region IsRefreshed
    /// <summary>
    /// IsRefreshed
    /// </summary>
    public bool IsRefreshed
    {
        get
        {
            string requestPath = HttpContext.Current.Request.Path;
            return (bool)HttpContext.Current.Items[requestPath + "_IsRefreshed"];
        }
    }

    #endregion
    /// 
    /// 重写OnPreRenderComplete,生成隐藏域CurrentTicket 
    /// 
    /// 
    protected override void OnPreRenderComplete(EventArgs e)
    {
        base.OnPreRenderComplete(e);
        string requestPath = HttpContext.Current.Request.Path;
        int ticket = int.Parse(HttpContext.Current.Items[requestPath + "_NextTicket"].ToString());
        ClientScript.RegisterHiddenField("CurrentTicket", ticket.ToString());
    }
}
    /// <summary>
    /// NoRepeatOperModule 的摘要描述
    /// </summary>
    public class NoRepeatOperModule : IHttpModule
    {
        public NoRepeatOperModule()
        {
            //
            // TODO: 
            //
        }

        /// <summary>
        /// 保存访问的页面记录,以页面路径为key, 标号为value
        /// </summary>
        static Hashtable historyRequest = null;

        /// <summary>
        /// 请求路径
        /// </summary>
        private string RequestPath
        {
            get
            {
                return HttpContext.Current.Request.Path;
            }
        }

        #region IHttpModule 成员

        public void Dispose()
        {
            //throw new Exception("The method or operation is not implemented.");
        }

        public void Init(HttpApplication context)
        {
            if (historyRequest == null)
            {
                historyRequest = new Hashtable();
            }

            context.BeginRequest += delegate(object sender, EventArgs e)
            {
                int lastTicket = GetLastTicket();
                int currentTicket = GetCurrentTicket(lastTicket);

                // 比较当前标号和上一个的标号,判断页面请求是否来源于刷新操作
                // 当前标号大于上一个标号 或初次请求都属于新的页面
                if (currentTicket > lastTicket || (lastTicket == currentTicket && currentTicket == 0))
                {
                    // 标记并保存页面请求是否来源于刷新的bool值
                    HttpContext.Current.Items[RequestPath + "_IsRefreshed"] = false;
                    historyRequest[RequestPath] = currentTicket;
                }
                else
                {
                    HttpContext.Current.Items[RequestPath + "_IsRefreshed"] = true;
                }
            };
        }

        #endregion

        /**/
        /// <summary>
        /// 获取某页面的上一个标号
        /// </summary>
        /// <returns></returns>
        private int GetLastTicket()
        {
            if (!historyRequest.ContainsKey(RequestPath))
            {
                return 0;
            }

            return int.Parse(historyRequest[RequestPath].ToString());
        }

        /**/
        /// <summary>
        /// 获取页面的当前标号
        /// </summary>
        /// <param name="lastTicket">上一个标号</param>
        /// <returns></returns>
        private int GetCurrentTicket(int lastTicket)
        {
            int ticket;
            // CurrentTicket 为页面的隐藏域的内容
            string currentTicket = HttpContext.Current.Request["CurrentTicket"];
            if (currentTicket == null)
            {
                ticket = lastTicket;
            }
            else
            {
                ticket = int.Parse(currentTicket);
            }

            // 保存页面的下一个标号
            HttpContext.Current.Items[RequestPath + "_NextTicket"] = ticket + 1;
            return ticket;
        }

    }

    //webconfig配置
    //<httpModules>
    //  <add name="NoRepeatOperModule" type="NoRepeatOperModule" />
    //</httpModules>