Under OSX programmatically control the master volume as well as register the volume change notification.
##The API header file
#ifndef LXMasterVolume_h
#define LXMasterVolume_h
//set master volume
void setMasterVolume(CGFloat volume);//0.0~1.0
//get master volume
CGFloat getMasterVolume();//0.0~1.0
//volume change notification name is LXMasterVolumeChangedNotification
//[[NSNotificationCenter defaultCenter] addObserver:self
// selector:@selector(volumeChanged:)
// name:@"LXMasterVolumeChangedNotification"
// object:nil];
//to get volume change notification
void startMasterVolumeChangeNotification();
void stopMasterVolumeChangeNotification();
#endif##Get the system volume
CGFloat volume=getMasterVolume();//range 0.0~1.0 ##Set the system volume
setMasterVolume(volume);//range 0.0~1.0 ##Get volume change notification
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(volumeChanged:)
name:@"LXMasterVolumeChangedNotification"
object:nil];
startMasterVolumeChangeNotification();
}
- (void)volumeChanged:(NSNotification*)n
{
CGFloat volume=getMasterVolume();
//volume changed
}##Stop volume change notification
stopMasterVolumeChangeNotification();
[[NSNotificationCenter defaultCenter] removeObserver:self
name:@"LXMasterVolumeChangedNotification"
object:nil];