flex: how to know preloader progress?

I know that preloader is the first piece downloaded and it will load the large part of the swf. I want to know the progress of the large part downloading, and for simplicity I don't need UI to display the开发者_如何转开发 percentage, the data will be passed to HTML, HTML will handle the UI.

Is there any easy way to get the preloader event in flex? Without adding a lot of code in flex?

Thanks.

You extend the download progress bar class and use it instead of the default. You can get the progress of the download then. Good example here