当用户单击asp.net中的浏览器后退按钮时，如何快速重定向页面

Question

I am building an application as server client concept, in which the server is an asp.net application. What i am trying to do is

1. User enter the link and provide the login details in the login page.
2. After authentication the user will be redirected to the main page, which is a master and child page.
3. Now when i click the sign out button (which is available in master page) the sessions are cleared and redirected back to the login page.this is fine.
4. But, When i try to click the back button in browser, i have been made to see the previous page and after few seconds i have been redirected back to the login page.

May i know the reason, when the browser back button is click whether the page load event will be fired or what is the process going on behind the screens.How can i make the page to redirect quickly.

Also i surfed the net and found that to avoid caching the page, i have added in all pages and master page, but no use of it. It remains the same.

Answer 1

就像您说的那样，您需要通过设置cache-control: no-cache标头来确保不缓存上一页，您可以在ASP.NET中使用以下命令执行此操作：

Response.Cache.SetCacheability(HttpCacheability.NoCache);

Answer 2

Actually browser caching is difficult with all browsers. You cant even be 100% certain its not being cached even if you do this (browsers do things on their own regardless of what you tell them, but this should cover most bases):

        Response.ExpiresAbsolute = DateTime.Now.AddDays(-1d);
        Response.Expires = -1500;
        Response.CacheControl = "no-cache";
        Response.AppendHeader("Cache-Control", "no-cache"); //HTTP 1.1 
        Response.AppendHeader("Cache-Control", "private"); // HTTP 1.1 
        Response.AppendHeader("Cache-Control", "no-store"); // HTTP 1.1 
        Response.AppendHeader("Cache-Control", "must-revalidate"); // HTTP 1.1 
        Response.AppendHeader("Cache-Control", "max-stale=0"); // HTTP 1.1  
        Response.AppendHeader("Cache-Control", "post-check=0"); // HTTP 1.1  
        Response.AppendHeader("Cache-Control", "pre-check=0"); // HTTP 1.1  
        Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1  
        Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1  
        Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1 
        Response.Cache.SetCacheability(HttpCacheability.NoCache);

Now also dont think that is enough. Firefox likes to cache with Url's, so if you ever link to a page you might need to change the URL by adding a timestamp to the end of it.

However if it isnt the cache that is causing the issue, then you can do some server side logic. Such as if the session doesnt exist in the codebehind, redirect in the code behind, this will redirect before any page is loaded. If the page does still load after this, then it is certainly a browser caching issue.