ASP.NET - Javascript timeOut Warning based on sessionState timeOut in web.config

Question

Problem: I am looking to create a time-out warning message on an asp.net page with a c# code behind based off my webconfig sessionState TimeOut Attribute.

Code on w

Answer 1

Pseudo code:

• Read the timeout setting in codebehind
• Register a ClientScriptblock (setTimeout passing the timeout period (20 * 60))
• On timeout, display a warning label on the page

Sample code:

    public void RegisterTimeoutWarning(System.Web.UI.Page Page)
    {
        var timeout = HttpContext.Current.Session.Timeout * 60 * 1000;
        Page.ClientScript.RegisterStartupScript(Page.GetType(), 
                "timeoutWarning", 
                string.Format("setTimeout(function () {{ alert('Session about to expire'); }}, {0});", timeout), true);
    }

Of course, you can improve the client side display (rather than showing an alert) by displaying warning popups or even a confirm popup which you can then use to renew the session.