Question

I want to store something in the Session object (i.e. a user ID), before anything else happens in a Page’s Life Cycle.
I tried putting it in the Page’s constructor, but the Session object isn’t yet available then.
I tried overriding OnInit, but then other delegates hooked to the Init event might still be executed prior.

I’m really lost, even though this feels like very basic ASP.NET theory.

Answer 1

A more usual approach is to encapsulate access to the data in Session, and load it on demand the first time it’s accessed. The basic pattern looks like the following:

public string UserId
{
    get
    {
        string s = Session["UserId"];
        if (s == null)
        {
            s = ... Get UserID from somewhere, e.g. database
            Session["UserId"] = s;
        }
        return s;
    }
}

In this way the data will be loaded the first time it’s needed, and you don’t need to care when that is in the page lifecycle.