Question

I have a list that I put in session:

Session.Add("SessionList", mylist);

How to retrieve it back from the session?

Answer 1

var list = Session["SessionList"] as List<whatevertypeYouUsed>;

if (list != null){
   // blah...
}

I prefer to use the as keyword since there is no 100% guarantee that the Session will contain the list (due to application pool refresh, website being restarted, etc). Gives you that extra bit of defence to avoid a NullReferenceException.