解决：

禁用客户端缓存

HTM网页

<META HTTP-EQUIV="pragma" CONTENT="no-cache">

<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache, must-revalidate">

<META HTTP-EQUIV="expires" CONTENT="Wed, 26 Feb 1997 08:21:57 GMT">

ASP网页

<%

Response.Expires = -1

Response.ExpiresAbsolute = Now() - 1

Response.cachecontrol = "no-cache"

%>

PHP网页

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

header("Cache-Control: no-cache, must-revalidate");

header("Pragma: no-cache");

JSP

response.setHeader("Pragma","No-Cache");

response.setHeader("Cache-Control","No-Cache");

response.setDateHeader("Expires", 0);

C#中禁止cache的方法！

Response.Buffer=true;

Response.ExpiresAbsolute=System.DateTime.Now.AddSeconds(-1);

Response.Expires=0;

Response.CacheControl="no-cache";  

或者

在<%@ Page language="c#" Codebehind="A.aspx.cs" Inherits="*.*" %>下面加上以下的代码：

<%@ OutPutCache Location="None"%>    能每次页面Load时都可以清空缓存