A lot has changed from ActionScript 2.0 to ActionScript 3.0, mostly for the best (but check out Colin Moock’s The Charges Against ActionScript 3.0, “O’Reilly InsideRIA Blog,” July 15, 2008.  With ActionScript 2.0, the details about how to build a good preloader evolved over time to a point where it became relatively easy and painless to add a preloader to your application that worked in just about all the browsers.

Boy, did all of that change with the introduction of ActionScript 3.0 -- at least if you were using custom classes and components in your flash applications, as most non-trivial flash applications do.

Now it is possible to take the basic ActionScript 2.0 approach and re-work it for ActionScript 3.0 -- in fact, Jamie Kosoy, Senior Developer at Big Spaceship, has written an excellent tutorial, ActionScript 3.0 for developers and designers – Part 1: Creating a preloader, but the techniques are involved. Still, you should make the time to work through Jamie’s tutorial, as you’ll learn a lot about the ActionScript 3.0 architecture and modular programming.

However -- if you’re looking for something easy, fast, and reliable, you’ve come to the right place.

This tutorial is based on the excellent preloading tutorial by Lee Brimelow at Adobe. You can actually watch him build this simple preloader on the gotoandlearn.com site. However, there’s no accompanying write-up, which is where this tutorial comes in.

I’ve broken this tutorial up into two sections.  If you just want the basics, and the code, without a lot of involved discussion, then just read Part I. In Part 2 I use the same code, but I show how this new preloading technique rests on the new Display API of ActionScript 3.0.

Ready?  Here we go!