If Not grdMain.IsFlyPostBack AndAlso Session(cSessionState_Expanded_WebGridRows) IsNot Nothing

If IsPostBack AndAlso Session(cSessionState_Expanded_WebGridRows) IsNot Nothing

and the problem doesn't happen in our local end. Hope this helps.

Regards,

Bernard

Hi Bernard,

Thanks for your reply and your solution. I'm not sure what caused this and why the Session object was empty while debugging, but changing this fixed the issue and now I can see content in the Session object.

Can you explain this a little more, to get some deeper understanding? I think I do understand the code, but this IsFlyPostBack property is not 100% clear to me. Why would that be there? I'm sure that got copied there for some reason, maybe from an example or so. And at least at some point this code worked.

From what I understand, the FlyPostBack is the dynamic postback done by JavaScript from your control and handled on the server-side just lika AJAX, by returning partially rendered content. When would this be called here (for sorting?) and why would we want to test for this property within the InitializeRow event handler?

And why would we need to even test for IsPostBack (in your new code)? Because even for initial load, we would like to expand the nodes as well (from the last visit of that page).

The problem is solved, but I'd like to get more understanding of what happened here and to avoid such mistakes in the future.

Thanks

Update: Today I had this problem again (Session empty in InitializeRow event handler). But it happened only with this sample, not in our real program. I did not make any other changes. Even restarting Visual Studio, closing all browsers, etc. did not help. After rebooting my PC (and deleting browser cache) everything seems to work again. It's probably not related to the cache, because I also tried to set all no-caching options in Page.Init event without success before rebooting. Is there any known bug related to this in V6? Anyway, this just confirms I was not dreaming yesterday that I saw the Session object empty and the questions above are still open.

Hi Bernard,

I suggest you forget the "Session empty" issue for now if there's no known bug. As mentioned, it gets fixed after reboot, so it might be something local or whatever. As long as the problem is solved in our main project by applying the discussed code change, we don't need to hunt these ghosts.

For the code, I removed the entire first part of the IF statement and just test if the Session object is there and in this case just apply the data (expand the node) - no checking of any kind of PostBack. I think that's the best way. I don't see any reason to test for PostBacks at all, because even for initial page load this should be done if the user returns to this page after visiting other pages.

The only open question is to understand all this. Why should we ever test for the IsFlyPostBack property here? This was probably copied from some sample code.

Eric