Flex performance considerations

Question

What are the main key-points a Flex developer should remember in order to improve performance of Flex applications? The ones which come to my mind are:

1. extending ItemRenderers from more lightweight base classes: i.e. UIComponent
2. using suspendBackgroundProcessing set to true for animations
3. using ArrayLists instead of ArrayCollections where appropriate.
4. useVirtualLayout in Spark DataGroups (unfortunately this step requires Scrollers to make this advice effective)
5. SQLight performance optimizations for AIR apps (transactions etc)
6. Probably splitting long data processing into different frames? (Never done this though, so I might be mistaken)

What are the key guidelines you try to follow while developing your Flex3/Flex4/AIR applications in order to increase their performance?

Answer 1

It seems to me a lot of people have performance issues w/ itemRenderers. So, my one contribution here to never use binding an itemRenderer. I fix a lot of customer "memory leak" bugs just by rewriting their itemRenderers to use the dataChange event instead of binding.

Beyond that, I second @Wade Mueller's comment about avoiding nested containers as much as possible.

Answer 2

Although this is less important with the lighter weight Spark Groups, I always try to keep the number of nested containers to a minimum and set explicit positions/sizes when possible. Complicated UIs with dynamically sized containers nested within one another cause a ton of (usually unnecessary) measuring to have to occur. This often results in huge lags when switching between views.

Answer 3

My list:

• use local vars instead of global as much as possible
• ActionScript instead of MXML as much as possible
• [Bindable] generates tons of code, try to avoid it

P.S. Автор, а ты русский язык знаешь? :)