asp.net c# MVC: How do I live without ViewState?

Question

I am just looking into converting WebForms to MVC:

In .net MVC, what concepts make ViewState something thats not required?

If a form is posted back on iteself etc (ie a postback)? how does the page/usercontrol maintain its state?

What tricks are people doing to maintain some kind of state and not resort to session state?

Surely, a completely stateless environment cant exist?

Answer 1

MVC has some advantages over WebForms but it also has some disadvantages as well as I covered detail in this answer. I think the fundamental question that you have to ask yourself is whether ViewState is a problem for you now - and is it such a problem that you must rewrite your application? If not, then Learning MVC is a worthy goal (it really is quite cool) but not one that I'd risk business for.

With that being said, ViewState can actually be disabled in a surprisingly large number of cases. It is used primarily to persist the value of controls through a post-back. So, for example, if you have a text box whose value you must check on the server side as well as a bunch of other fields, ViewState will let you handle the post-back, catch the error (and show a label) and then return the user to the form with all of their entries intact. However, if a form is only going to be filled out and posted back and you'll then be redirecting to another page, you can safely disable it.

Finally, you ask what people are doing to avoid Session state. Is there a reason to avoid session state? Surely you don't want much information there but avoiding it altogether is really not necessary and, in fact, will cost you one of the most powerful tools in your arsenal.