These keys are usually handled by media players, even when they are running in the background, while volume control is handled by Windows.
However, when FC is in foreground, these buttons stop working.
Steps to reproduce:
- Launch any media player and start playing some music
- Make any FC window active
- Try adjusting volume using the keyboard
Volume control buttons don't work when FC window is active. If you switch focus to another window, they will work.
Volume control buttons should work regardless whether FC is an active window or not.
Cause of the bug:
The problem is caused by incorrect handling of WM_APPCOMMAND notification in FC. MSDN says that applications should return TRUE if they process the message: http://msdn.microsoft.com/en-us/library ... S.85).aspx
Therefore, it appears that FC returns TRUE even if it doesn't process the message, preventing other applications to respond to the command keys.
Adjust the code so that it returns FALSE when it does not process WM_APPCOMMAND message.