CODEWITHSUNDEEP
asp.net
Precise Tech
Precise Tech

Reputation: 173

why ViewStates instead of Sessions

why we use to store data in ViewState? even we have Sessions to do the same job?

Session["Data"]

vs.

ViewState["Data"]

What's the difference?

Upvotes: 4

Views: 75

Answers (3)

Arunprasanth K V
Arunprasanth K V

Reputation: 21901

**Session**



Session state is maintained in session level.

  Session state value is available in all pages within a user session.
    - 
  Session state information stored in server.
    - 
  Session state persist the data of particular user in the server.
    This data available till user close the browser or session time
    Completes.
    -
 Session state used to persist the user-specific data on the server
    Side

View state 

    View state is maintained in page level only. 
    View state of one page is not visible in another page.        
    View state information stored in client only.       
    View state persist the values of particular page in the client
  (browser) when post back     operation done.

Upvotes: 1

Yaman
Yaman

Reputation: 1061

ViewState applies on the page you are currently in and is stored on the client machine as a hidden field __ViewState, and is encrypted with Base64

While Session is stored on the server and in the scope of the whole user session, it is removed when the user leaves your site and the session expires (by default 20 minutes of inactivity) or you explicitly call Session.Abandon() on logout for example

You have to be careful when using session that it does not contain big objects, as when there are more active sessions, the memoru will be filled up.

And be careful when using big objects with ViewState, as its stored on the clients and goes back and forth with post backs.

Upvotes: 1

Patrick Hofman
Patrick Hofman

Reputation: 156898

Session data is valid only when the current session is active. Usually the server deletes the session after half an hour or so. The ViewState is available, even when the session is expired and you still have the page on screen. That content is serialized in the view, and it is send over the network every time you open the page, or send a form back.

Another thing is this: When you have multiple instances of one page where you want to keep a name for example, you don't want two open instances of the form share the same variables. Instead, you save it in the View, where you have it available for that page, and that page only.

Upvotes: 0

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