saving and retrieving values from session state in asp.net

Question

I am reviewing some web code and I am not exactly sure how ASP.net session state works. Any helps would be gratefully appreciated.

If a User object is saved to the session state during login, and User.FirstName and User.LastName is set. If other web pages retrieve the user object from the session and set the FirstName to something else is that persisted on other web pages? Or, do you need to re-add the user object back to the session once it has been modified? Thanks

RPM1984 · Accepted Answer · 2010-12-20 11:12:22Z

Session is persisted on the server, but tracked via the client. I repeat - via the client.

In most cases, sessions are tracked with cookies. So using your example, when User object is saved to Session:

Session["UserInfo"] = new User { FirstName = "Joe", LastName = "Bloggs" };

A cookie will be sent to the client with a unique identifier. This cookie is passed along to all further HTTP requests from this client/browser unless it expires.

If another user comes along (from a different machine) for the first time, Session["UserInfo"] will be null.

An alternative to cookies is "cookieless-session" - where instead of using a cookie to store the session identifer - the identifier is tacked onto the URL.

So the answer is no - other web pages (e.g other clients/machines/browsers) will not have access to this information.

If you want information shared between different clients from the web server, use Cache.

However given the context of the question (User information), it is valid to store this information in the Session, as it is only relevant to a particular user (shouldn't be shared).

An alternative a lot of people use instead of sticking the User info in the session, is to put it in a generic principle which get's attached to the Forms Authentication ticket.

Up to you which road you choose.

immutabl · Accepted Answer · 2012-03-26 08:18:46Z

2

This should help you get your head around Sessions in ASP.Net

~~http://www.codeproject.com/KB/aspnet/ExploringSession.aspx~~ http://www.codeproject.com/Articles/32545/Exploring-Session-in-ASP-Net

edited Mar 26, 2012 at 8:18

answered Dec 20, 2010 at 12:23

immutabl

6,89413 gold badges47 silver badges76 bronze badges

Comments

Mud · Accepted Answer · 2010-12-20 11:05:02Z

1

Any changes you make to the object are persisted.

answered Dec 20, 2010 at 11:05

Mud

29.2k12 gold badges64 silver badges100 bronze badges

2 Comments

Bobbo Over a year ago

OK, so if on my page I retrieve my user object via the session and set my page level user variable. If I update the user object via the page level variable, it will automatically update the session user object?

Mud Over a year ago

Yes. Unless your app is running on a server farm, your session data is just an object held in server memory (inproc). ASP.NET figures out which client a request is coming from by an id, then uses that ID to make sure the right session dictionary is the code handling the request, but it doesn't alter the dictionary. Any changes you make to it or any objects it points to persist.

Collectives™ on Stack Overflow

saving and retrieving values from session state in asp.net

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related