Some important notes you have to keep in mind when migrating Flex 2 to Flex 3 (via
http://kuwamoto.org/2006/05/08/tips-for-flex-2-beta-3/) :
* flash.util has been renamed flash.utils
* Several things have been renamed from hXXX to horizontalXXX.
* There are times when you have to cast Application.application to DisplayObject
* DataProvider APIs are no longer on the list classes. For example, you can no longer say myList.getItemAt(index). Instead, say myList.dataProvider.getItemAt(index).
* ICollectionView.getCursor() has been renamed ICollectionView.createCursor().
* You no longer have to manually release the iterators you get back from the createCursor() function.
* The constructor for CollectionEvent now takes an attribute to specify the event type.
There were a couple things that tripped me up during migration that you might want to watch out for:
* If you use states… the “target” property of the AddChild tag has been renamed “relativeTo”. Unfortunately, the “target” property still exists, but it now means something different. My suggestion is to do a search for AddChild and change “target” to “relativeTo” as one of the first things you do in moving to beta 3. If you forget to do this, you get a somewhat cryptic runtime error (”Cannot add a child that is already parented”) when you switch into that state.
* If you use trace… Don’t worry when it tells you that flash.util.trace is an invalid import. You no longer need to import anything to use trace.