Question

I want a certain segment of code to be executed only once per session, so if the user navigates to the page containing this code while within the same session, I don’t want this segment to be executed. The code lives in a default page that is called right after login, and user can navigate to this default page from other pages.

My Solution:

if (Session["MySessionName"] == null && ConditionTwo) //initially MySessionName won't exist so the if condition resolves to true
{
    //Assign Value to MySessionName so the if condition resolves to false next time
    Session["MySessionName"] = "MySessionValue";
    //Do Something
}

My Problem:

This works fine on visual studio, after deploying to test server this solution doesn’t seem to work all the time. If I log out and log back in, the condition Session["MySessionName"] == null returns false and the code segment won’t be executed. However if I close the browser, reopen, and log in, it works fine. I have checked if the logout did a proper session dispose and it does.

I also tried,

HttpContext.Current.Session["MySessionName"] = "MySessionValue"; 
//and 
Session.Add("MysessionName", true);

but result was the same.

Answer 1

If you are using forms authentication, you need to call FormsAuthentication.SignOut().

In addition, on logout you need to call Context.Session.Abandon() to terminate the current session.

I also make sure that I always explicitly clear any sensitive or user-related values from the session state prior to abandoning the session.