Which version of Flex SDK should I use to support Flash Player10.0?

Question

I'm developing a Flash application by using Flex SDK, actionscript, and text editor and compiling AS file in command line.

According to Flash Player Version Penetration on Adobe's web site:
http://www.adobe.com/products/player_census/flashplayer/version_penetration.html

Rate of people who use Flash Player 10.1 and 10.2 is not enough.

So, I want to make my flash application to support Flash Player 10.0 because I want more people to use my application.

Target Player of Flex SDK 4.5.1 and 4.5.0 is Flash Player 10.2.0.
Target Player of Flex SDK 4.1.0 and 4.0.0 is Flash Player 10.0.0.
Target Player of Flex SDK 3.5.0 is Flash Player 9.0.124.

To support Flash Player 10.0, should I use Flex SDK 4.1.0 instead of the latest version Flex SDK 4.5.1?
Or is it better to use Flex SDK 3.5.0 to support Flash Player 9, too?

Answer 1

I would recommend using the latest version of SDK that supports the version of Flash Player you need to support. You can specify which runtime player you want to target using the target-player compiler argument. Generally, like this:

-target-player=10.0 

More info. To quote some relevant passages:

For Flex 4.0, the only supported value of the target-player option is 10.0.0. For Flex 4.1, the default value is 10.1.0. For Flex 4.5, the default value is 10.2.0.

The minimum value for Flex 4.5 is 10.2.0. For Flex 4.0 and 4.1, the minimum value is 10.0.0 (although Flex 4.1 included Player 10.1).

Answer 2

If penetration rate is that important to you, ask yourself - does Flex 4.x have anything you really need? 3.5 is a good SDK (and in some ways adding Spark introduced some complexities), it's major shortcomings that I can recall (IMO - I'm not a Spark fan) would be:

• No two-way bindings
• Porting to 4.x down the road will be a pain due to the namespace changes

If you aren't concerned about these things, and you don't really want to take advantage of any of the other new features in 4.x, I'd just use 3.5. For example, if you really need heavy UI customization, you do want to use Spark - so you'd want 4.x. (4.1 seems a decent compromise.)