http://stackoverflow.com/questions/2701 ... r-is-moved
The other thing is, if the taskbar is at the top or on the left edge, the Right number will not be the resolution width and the bottom number will not be the resolution height. You have to do b - t to get the height and r - l to get the width. Also if AutoHide is enabled on the taskbar, GetWorkArea API will just return the screen resolution. You have to let your users know that AutoHide must be disabled for your utility to work(or use some other technique.)
From my playing around it seemed to me that screen resolution change notification worked fine. But taskbar position change notification wasn't worth diddly.
Edit: I don't know what your utility will do but for my stuff, moving things around when the user hits a hotkey, I just calculate the work area every time the user hits the hotkey, rather than trying to be notified by the system. It's way more reliable.
"My plan is to ghostwrite my biography. Then hire another writer to put his
name on it and take the blame."
- MilesAhead