FEATURE REQUEST: can xfce handle multimedia key like in Gnome that is configure eject, volume up and down key to behavior like for brightness keys osd thanks
No, this isn't something that goes in the core. Try xfce4-volumed for something that handles the volume keys. xfce4-power-manager will handle the brightness keys. Not sure about the eject key, but you can bind it to something if you want in the keyboard settings.
i ask about a notification like in brightness
xfce4-pulseaudio-plugin should perform this function, but it seems to be in a state of disrepair, or at least, this particular bit of functionality is not functioning at the moment.