Logoff User when browser tab page is closed, ASP.NET MVC

Question

In one of the ASP.NET MVC apps we would like to logoff the user automatically if he closes the browser tab in which the app is opened.

We are using the following code wh

Answer 1

You can simply use session variables to automatically log off anybody trying to return to the secured destination page. Create a single session variable (integer or boolean) and in the onclick event of your login button reset it to a known state after acknowledging that the user has a valid credential then set or increment that session variable in the page_load event of the page your trying to secure. Test these values and signout the user if he is trying to return to the page or do nothing if otherwise. The code may look similar to this.

protected void btnLogin_Click(object sender, EventArgs e)
 {
         if (IsAuthenticated == true)
         Session["IsUserLoggedIn"] = (int)0;
 }

 protected void Page_Load(object sender, EventArgs e)
{
    if (HttpContext.Current.User.Identity.IsAuthenticated == true)
                {
                        if (Session["IsUserLoggedIn"] != null)
                        {
                                int IsUserLoggedIn = (int)Session["IsUserLoggedIn"];
                                if (IsUserLoggedIn <= 0)
                                {
                                        Session["IsUserLoggedIn"] = (int)IsUserLoggedIn + 1;
                                }
                                else
                                {
                                        Session["IsUserLoggedIn"] = (int)0;
                                        FormsAuthentication.SignOut();
                                        FormsAuthentication.RedirectToLoginPage();
                                }
                        }
                }
                else { Session["IsUserLoggedIn"] = (int)0; } 
        }