Im trying to build a system tray program which allows you to hover over the icon and it displays the volume percentage of the pc, maybe even getting the icon to display the current volume setting.

Is there any way of retreiving the main system volume (not the wave volume, the master volume) and converting it to a percentage?

Also, if the above is possible. Is there a way to update the volume shown only when the volume changes rather than constantly retreiving the current volume every few seconds whether it has changed or not?