draw background for DataGrid columns

When I read Peter Ent's post about "Coloring the Background of Cells", I need to fill the column in my project, which is programmatically generated, with gradient background fill.
I didn't finish my job at the first try. After I read the post again, I found each column has to be assign a backgroundColor style before DataGrid drawColumnBackground function taking effect.
This function "drawColumnBackground" is called by drawLinesAndColumnBackgrounds function, which is called in updateDisplayList function. So I think I can update each column background by override the updateDisplayList function. I probabely need to update datagrid data as well as column background based on user action.

Reading for Custom Flex Preloader

I've read Ted's Flex 2 Preloader before I implemented a preloader class in my project.
However this class seems not working as I expected. Loading is quite glitch. I found in the code there is time interval to check status and display preloader, which slow down the process of loading animation.
After a couple of months, I retrieve this problem and found some new entries explained in detail how the preloading proceed and which class is not good to be used in preloader class.

• Flex 3 Pleloading Explained is new and has upcoming post(not posted yet) to explain the preloading in Flex;
• Custom Flex 3 Lightweight Preloader gives a very good example to build an preloader;
• Implementing A Flex 2 Custom Preloader has one Class from basic implementation of IPreloaderDisplay which is simple and detail explained.

I hope I can try to redo this preloader next week for my project.

Flex memory leaks and garbage collection

I read a series of blogs talking about memory leak and garbage collection in Flex.
It's very good resource to gain the knowledge about garbage collection in Flex.
Here is the post and following the other 4 posts from We are the heroes of Web 2.0