ASP.NET Push Redirect on Session Timeout

Question

I\'m looking for a tutorial, blog entry, or some help on the technique behind websites that automatically push users (ie without a postback) when the session expires. Any h

Answer 1

Well this gets tricky for AJAX requests as Zhaph - Ben Duguid pointed out. Here was my solution to make this work with AJAX (using Telerik web controls but they are built using ASP.NET AJAX toolkit I believe).

In a nutshell, I rolled my own sliding expiration session type thing.

In my Site.Master, I am updating a session variable on EVERY postback (postback or AJAX request because AJAX requests still kick off the Page_Load event):

protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            if (this.Request.IsAuthenticated)
                this.pnlSessionKeepAlive.Visible = true;
            else
                this.pnlSessionKeepAlive.Visible = false;
        }

        if (this.Session["SessionStartDateTime"] != null)
            this.Session["SessionStartDateTime"] = DateTime.Now;
        else
            this.Session.Add("SessionStartDateTime", DateTime.Now);
    }

Then in my markup for my site.master, I included an iframe with a ASPX page I use "behind the scenes" to check and see if my custom sliding expiration has expired: