It seems there is a bug or at least an annoynance with the new eventvalidation .
I can't really tell you a certain way to reproduce this but I have a large datagrid that
uses custom paging, I have navigation controls both at the top and the bottom.
Everything works fine if you click the navigation links and allow the page to fully
load before clicking the next time, but sometimes people click the navigation links
at the top before the page has fully loaded, and behold, the dreaded "yellow page"
appears:
Server Error in '/' Application.
--------------------------------------------------------------------------------
Invalid postback or callback argument. Event validation is enabled using <pages enableEventVali dation="true"/> in configuration or
<%@ Page EnableEventVali dation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or
callback events originate from the server control that originally rendered them.
....<snip>
The whole problem here seem to be that the hidden form field __EVENTVALIDATI ON is placed
at the very bottom of the page, just above the closing form tag, so if the page isn't fully loaded when
they click the "next" link this field is either not sent along or is corrupted.
So, BUG or annoyance ? You decide, it seems to me this is a buggy implementation to say the least
and it may appear intermittently all over an application just because a postback happens from a page
that haven't fully loaded.
It would be nice to MS comments on this, and how to solve it other than turning eventvalidation off
for the whole application.
PL.
