This post will most probably apply to the GridView and LoginView controls as well.
The Problem
Lets assume that you've successfully bound a listview to your datasource and configured all the properties on the listview to display the Select/Edit/Delete links. You then have the task to write the logic in the appropriate events of the usercontrol/sublayout. While I was implementing the Edit functionality, I implemented the OnItemCommand event of the Listview to display an Edit Panel with the data populated from the selected row. I was a bit suprised to see that the end result wasn't what I was expecting:
The Edit Panel shows up but the Listview has left the party.!!
The Frustration
It dawned on me that, at some point, I must have messed up somewhere in the code.So, I began putting "EnableViewState=true" to every control.. (this shows how desperate I was!!). I also reverted to "AutoEventFireUp=false" (Originally, I was manually hooking up the events..).I tried databinding on every possible method I could lay my hands on!!. I lost confidence on the fact that this was a really easy task and yet, it was taking me hours to get to the bottom of the problem. I completely lost my mind....I began googling on the issue ["postback..losing viewstate"], I started to watch a few videos that demonstrate the functionality of the ListView..I even got the point where I created another item in Sitecore, assigned the same sublayout to the item's presentation and accessed the item using the url.. I ended up in the same situation.... I surrendered...I left the battlefield...wounded..!!
].
The Solution
I finally blamed it on Sitecore!! Who knows, maybe it was a known issue in one of their releases or maybe I just needed to upgrade to the latest stable release(090120). Out of desperation, I tried searching on the Forums and found that I wasn't the only one experiencing this issue.I came across this forum post. Thanks to Mark Cassidy, I eventually finished my task (It had taken me almost a day...and that had messed up (big time) on my initial estimate!!!)
The solution, as Mark outlined, is to add the type of the control (in my case, System.Web.UI.WebControls.ListView) to the typesThatShouldNotBeExpanded element in the web.config. Presumably, for the sake of consistency, you might also append the System.Web.UI.WebControls.Gridview to the list (in case your website makes use of one!!). From what I've read so far, no one knows about the purpose of the typesThatShouldNotBeExpanded element .!! {Sigh...Sitecore!! What did you do that to me????}
In hindsight, only laughs...Good Days...Good Times...
I hope this helps someone!!!
Back to Sitecore ......