I've 2 asp.net pages..page A and page B. On clicking a link on page A, user gets redirected to page B.When on page B, if user clicks browser's back button, I need to forcefully invoke page refresh of page A. How do I achieve this functionality? Note:Code needs to be compatible across different browsers...ie IE, firefox, opera, etc
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6 Answers
There is some button property like Autopostback, you can try it and see if ti helps!
Comments
I think there is no way for Javascript to tell whether it is the first visit or coming from the back button. So I put the parts of the page that need to be updated in an UpdatePanel, and then do the JavaScript to always refresh these on every page load. Not very elegant but it fixes my problem.
function addLoad(fn) { if (window.addEventListener) { window.addEventListener("load", fn, false); return true; } else if (window.attachEvent) { var r = window.attachEvent("onload", fn); return r; } else { return false; } } function refreshBack() { __doPostBack("<%= updatePanel1.ClientID %>", ""); __doPostBack("<%= updatePanel2.ClientID %>", ""); } addLoad(refreshBack); 
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You could set a session variable on page B and check to see if that session variable exists on page A and handle it accordingly.
2 Comments
Steve Chapman
thanks...but will browser's back button click invoke Page_Load method of page A?
Chad Grant
No, not guaranteed. You'll have to use Javascript, its the only thing that is guaranteed to run on a cached page.
I'd say the best way to do it is telling the browser not to cache the page.
<% Page.Response.Expires = 0; %> If that doesn't work to your needs, you'd need javascript to force the refresh.
Psuedo code:
if (cookie does not exist) set cookie with 10 second expiration else if cookie exists { is cookie expired? { set new cookie refresh page } } 
2 Comments
jamesmillerio
A word of warning, setting the expiration time to 0 will throw a "Webpage has expired" error in IE7 and force the user to refresh the page. This might throw your users off if they see that error page.
Steve Chapman
how do i refresh an asp.net page using javascript?
function SetCookie (name, value) { var argv=SetCookie.arguments; var argc=SetCookie.arguments.length; var expires=(argc > 2) ? argv[2] : null; var path=(argc > 3) ? argv[3] : null; var domain=(argc > 4) ? argv[4] : null; var secure=(argc > 5) ? argv[5] : false; document.cookie=name+"="+escape(value)+ ((expires==null) ? "" : ("; expires="+expires.toGMTString()))+ ((path==null) ? "" : ("; path="+path))+ ((domain==null) ? "" : ("; domain="+domain))+ ((secure==true) ? "; secure" : ""); } function getCookie(c_name) { var c_value = document.cookie; var c_start = c_value.indexOf(" " + c_name + "="); if (c_start == -1) { c_start = c_value.indexOf(c_name + "="); } if (c_start == -1) { c_value = null; } else { c_start = c_value.indexOf("=", c_start) + 1; var c_end = c_value.indexOf(";", c_start); if (c_end == -1) { c_end = c_value.length; } c_value = unescape(c_value.substring(c_start,c_end)); } return c_value; } if (getCookie('first_load')) { if (getCookie('first_load')==true) { window.location.reload(true); // force refresh page-liste SetCookie("first_load",false); } } SetCookie("first_load",true); 
Comments
You could try doing it this way
protected override void OnInit(EventArgs e) { //Refresh page on back button Response.Cache.SetCacheability(HttpCacheability.NoCache); Response.Cache.SetNoStore(); Response.Cache.SetExpires(DateTime.MinValue); base.OnInit(e); } 