TrapRefreshPage改进版
捕捉刷新事件
参考了以下文章
http://msdn2.microsoft.com/en-us/library/ms379557(VS.80).aspx
做了一些改进,把计数器放到Cookie中,不使用HttpMoudle,不用在每个按钮事件里加TraceSatae方法,不用每次页面请求时都判断
主要实现类
CS页
参考了以下文章
http://msdn2.microsoft.com/en-us/library/ms379557(VS.80).aspx
做了一些改进,把计数器放到Cookie中,不使用HttpMoudle,不用在每个按钮事件里加TraceSatae方法,不用每次页面请求时都判断
主要实现类
public static class RefreshTracker
{
Constants
private static int GetLastRefreshTicket(HttpContext ctx)
{
if (ctx.Request.Cookies[RefreshTracker.LastRefreshCounter] == null)
{
HttpCookie cookie = new HttpCookie(LastRefreshCounter, "0");
ctx.Response.Cookies.Add(cookie);
}
return Convert.ToInt32(ctx.Request.Cookies[LastRefreshCounter].Value);
}
/// <summary>
/// 从HiddenField中取出当前的刷新次数
/// </summary>
/// <param name="ctx"></param>
/// <returns></returns>
private static int GetCurrentRefreshTicket(HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
return Convert.ToInt32(ctx.Request[HiddenFieldRefreshCounter]);
}
/// <summary>
/// 更新最后刷新记数器
/// </summary>
/// <param name="ctx"></param>
/// <param name="ticket"></param>
private static void UpdateLastRefreshCounter(HttpContext ctx, int ticket)
{
if (ctx.Request.Cookies[RefreshTracker.LastRefreshCounter] == null)
{
HttpCookie cookie = new HttpCookie(LastRefreshCounter, "0");
ctx.Response.Cookies.Add(cookie);
}
ctx.Response.Cookies[LastRefreshCounter].Value = ticket.ToString();
}
public static bool Check(HttpContext ctx)
{
//从Cookie中读出最后一次刷新记数
int lastTicket = GetLastRefreshTicket(ctx);
//从Cookie中读出当前的刷新记数
int thisTicket = GetCurrentRefreshTicket(ctx);
// 如果当前刷新记数大于或等于最后次刷新记录数,说明是用户提交
if (thisTicket > lastTicket ||
(thisTicket == lastTicket && thisTicket == 0))
{
//更新最后一次刷新记数
UpdateLastRefreshCounter(ctx, thisTicket);
return false;
}
else
{
return true;
}
}
/// <summary>
/// 跟踪刷新,当用户点击后,将当前记数器加上1
/// </summary>
/// <param name="ctx"></param>
public static void TrackRefreshState(HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
int ticket = Convert.ToInt32(ctx.Request.Cookies[CurrentRefreshCounter].Value) + 1;
ctx.Response.Cookies[CurrentRefreshCounter].Value = ticket.ToString();
}
/// <summary>
/// 保存刷新记数到当前记数器和HiddenField
/// </summary>
public static void SaveRefreshState(Page page, HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
int ticket = Convert.ToInt32(ctx.Request.Cookies[CurrentRefreshCounter].Value) + 1;
ctx.Response.Cookies[CurrentRefreshCounter].Value = ticket.ToString();
//将当前刷新数写入HiddenField,这样,当用户点刷新后,HiddenField中的值不会被加1
page.ClientScript.RegisterHiddenField(RefreshTracker.HiddenFieldRefreshCounter, ticket.ToString());
}
}
调用页面和示例代码{
Constants
private static int GetLastRefreshTicket(HttpContext ctx)
{
if (ctx.Request.Cookies[RefreshTracker.LastRefreshCounter] == null)
{
HttpCookie cookie = new HttpCookie(LastRefreshCounter, "0");
ctx.Response.Cookies.Add(cookie);
}
return Convert.ToInt32(ctx.Request.Cookies[LastRefreshCounter].Value);
}
/// <summary>
/// 从HiddenField中取出当前的刷新次数
/// </summary>
/// <param name="ctx"></param>
/// <returns></returns>
private static int GetCurrentRefreshTicket(HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
return Convert.ToInt32(ctx.Request[HiddenFieldRefreshCounter]);
}
/// <summary>
/// 更新最后刷新记数器
/// </summary>
/// <param name="ctx"></param>
/// <param name="ticket"></param>
private static void UpdateLastRefreshCounter(HttpContext ctx, int ticket)
{
if (ctx.Request.Cookies[RefreshTracker.LastRefreshCounter] == null)
{
HttpCookie cookie = new HttpCookie(LastRefreshCounter, "0");
ctx.Response.Cookies.Add(cookie);
}
ctx.Response.Cookies[LastRefreshCounter].Value = ticket.ToString();
}
public static bool Check(HttpContext ctx)
{
//从Cookie中读出最后一次刷新记数
int lastTicket = GetLastRefreshTicket(ctx);
//从Cookie中读出当前的刷新记数
int thisTicket = GetCurrentRefreshTicket(ctx);
// 如果当前刷新记数大于或等于最后次刷新记录数,说明是用户提交
if (thisTicket > lastTicket ||
(thisTicket == lastTicket && thisTicket == 0))
{
//更新最后一次刷新记数
UpdateLastRefreshCounter(ctx, thisTicket);
return false;
}
else
{
return true;
}
}
/// <summary>
/// 跟踪刷新,当用户点击后,将当前记数器加上1
/// </summary>
/// <param name="ctx"></param>
public static void TrackRefreshState(HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
int ticket = Convert.ToInt32(ctx.Request.Cookies[CurrentRefreshCounter].Value) + 1;
ctx.Response.Cookies[CurrentRefreshCounter].Value = ticket.ToString();
}
/// <summary>
/// 保存刷新记数到当前记数器和HiddenField
/// </summary>
public static void SaveRefreshState(Page page, HttpContext ctx)
{
if (ctx.Request.Cookies[CurrentRefreshCounter] == null)
{
ctx.Response.Cookies.Add(new HttpCookie(CurrentRefreshCounter, "0"));
}
int ticket = Convert.ToInt32(ctx.Request.Cookies[CurrentRefreshCounter].Value) + 1;
ctx.Response.Cookies[CurrentRefreshCounter].Value = ticket.ToString();
//将当前刷新数写入HiddenField,这样,当用户点刷新后,HiddenField中的值不会被加1
page.ClientScript.RegisterHiddenField(RefreshTracker.HiddenFieldRefreshCounter, ticket.ToString());
}
}
CS页
/// <summary>
/// 判断当前的请求是否为用户刷新(如按F5)
/// </summary>
public bool IsPageRefresh
{
get
{
return RefreshTracker.Check(this.Context);
}
}
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
RefreshTracker.SaveRefreshState(this, this.Context);
}
protected override void RaisePostBackEvent(IPostBackEventHandler sourceControl, string eventArgument)
{
RefreshTracker.TrackRefreshState(this.Context);
base.RaisePostBackEvent(sourceControl, eventArgument);
}
protected void Button1_Click(object sender, EventArgs e)
{
if (!this.IsPageRefresh)
{
Response.Write("Action");
}
else
{
Response.Write("IsPageRefresh");
}
}
HTML页
/// 判断当前的请求是否为用户刷新(如按F5)
/// </summary>
public bool IsPageRefresh
{
get
{
return RefreshTracker.Check(this.Context);
}
}
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
RefreshTracker.SaveRefreshState(this, this.Context);
}
protected override void RaisePostBackEvent(IPostBackEventHandler sourceControl, string eventArgument)
{
RefreshTracker.TrackRefreshState(this.Context);
base.RaisePostBackEvent(sourceControl, eventArgument);
}
protected void Button1_Click(object sender, EventArgs e)
{
if (!this.IsPageRefresh)
{
Response.Write("Action");
}
else
{
Response.Write("IsPageRefresh");
}
}
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" ValidateRequest="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
</form>
</body>
</html>