I have an ASP.NET web page that displays a variety of fields that need to be updated best on certain conditions, button clicks and so on. We've implemented AJAX, using the ASP.NET Update Panel to avoid visible postbacks.
Originally there was only one area that needed this ability ... that soon expanded to other fields. Now my web page has multiple UpdatePanels.
I am wondering if it would be best to just wrap the entire form in a single UpdatePanel, or keep the individual UpdatePanels.
What are the best practices for using the ASP.NET UpdatePanel?
Multiple panels are much better. One of the main reasons for using UpdatePanels at all is to reduce the traffic and to only send the pieces that you need back and forth across the wire. By only using one update panel, you're pretty much doing a full post back every time, you're just using a little Javascript to update the page without a flicker.
If there are pieces of the page that need to be updated together, there are ways to trigger other panels to update when one does.. but you should definitely be using multiple update panels.