Asp.net - Do changes to session objects persist?

Question

I'm using the session to hold a custom object UserSession and I access the session like this:

UserSession TheSession = HttpContext.Current.Session["UserSession"] as UserSession;

Then, in my code, I modify a property of TheSession like this

TheSession.Prop1 = some new value;

My question is this: when I change the value, does it change the value inside the session that's in HttpContext.Current.Session["UserSession"] or just the TheSession variable, in which case I'd need to reassign the object variable to the session.

Thanks.

score 4 · Accepted Answer · edited May 23 '17 at 12:17

4

The standard session provider is a simple dictionary that stores objects in memory.

You're modifying the same object that you put in the session, so the modifications will persist.
(unless you're using an evil mutable struct)

edited May 23 '17 at 12:17

Community

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answered Jun 17 '11 at 02:46

SLaks

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I'm declaring TheSession object like this: public class TheSession {...} Am I in the clear? – frenchie Jun 17 '11 at 03:04
That's a class, not a struct. – SLaks Jun 17 '11 at 03:06
ok, cool; thanks for your clarification, very much appreciated. I'll never use a struct:) – frenchie Jun 17 '11 at 03:14
I'm not saying to never use a struct; I'm saying to never use a **mutable** struct. (one that can change) – SLaks Jun 17 '11 at 12:11
ok, I'll keep that in mind: use a struct if its content is never intended to be changed (let me know if that's right). – frenchie Jun 18 '11 at 02:52
Not **able** to be changed. And only if it's reasonably small (4-8 bytes), and represents a value. – SLaks Jun 19 '11 at 02:09

score 4 · Answer 2 · answered Jun 17 '11 at 02:56

Yes it is the same object. It is very easy to see in the following example:

Session["YourObject"] = yourObject;
yourObject.SomeProperty = "Test";
var objectFromSession = (YourObjectType)(Session["YourObject"]);
Response.Write(objectFromSession.SomeProperty);

The Write will display: Test

score 1 · Answer 3 · answered Jun 17 '11 at 02:59

create a static class with static properties:

public static class UserSession
{
    public static int UserID
    {
         get { return Convert.ToInt32(Session["userID"]); }
         set { Session["userID"] = value; }
    }
}

When u use it:

UserSession.UserID = 23;
Response.Write(UserSession.UserID);

it will use the session variable to store information passed to this property.

score 0 · Answer 4 · answered Jun 17 '11 at 02:47

0

It doesn't need to reassign the object. Because both of them are pointing to same instance in memory

answered Jun 17 '11 at 02:47

Peyman

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Asp.net - Do changes to session objects persist?

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