I took me a couple of hours of messing around to finally figure out that there is just no way to get a Flex app to see the CSS settings I have for “headerStyleName”. In Flex 3 they had it working but in Flex 4 it’s busted. This bug has been filed in FLEXDMV-2329 and FLEXDMV-2489 in JIRA bugbase but no joy. Obviously because they are working towards getting the Spark Datagrid out. But until they get the Spark Datagrid up to snuff (which isn’t an obvious timeframe), it’s tough cookies for us all.
The only “workaround”, which isn’t really, is to use a custom skin for the headerBackgroundSkin. Sucks.. but can work for the most part. Anyways, since I spent so much time trying to figure out why it wasn’t working I thought I’d put it out there for others to search and find to hopefully save them time. Thanks Adobe for busting good functionality… 😛