ASP.net ViewState

Question

where is asp.net testing if a viewstate is valid and what happens if it is not valid?

Do I have to validate the ViewState by myself?

Asp.net 3.5

BR Thanks

Answer 1

where is asp.net testing if a viewstate is valid and what happens if it is not valid?

You'll get an exception if ViewState is invalid.

The ViewState is validated when the page is posted back and it happens before the Page_Load (LoadViewState green box on the pic below) event is raised. Read here. for more details

Answer 2

I can only recommend you reading this excellent article about ViewState and the ASP.NET lifecycle. It opened my eyes and I think it would help you understand how ViewState works. It has a section about validation and security:

http://msdn.microsoft.com/en-us/library/ms972976.aspx