private static ISimpleAudioVolume GetVolumeObject(int pid, IMmDevice device)
{
// activate the session manager. we need the enumerator
Guid iidIAudioSessionManager2 = typeof(IAudioSessionManager2).GUID;
device.Activate(ref iidIAudioSessionManager2, 0, IntPtr.Zero, out object o);
IAudioSessionManager2 mgr = (IAudioSessionManager2)o;
// enumerate sessions for on this device
mgr.GetSessionEnumerator(out IAudioSessionEnumerator sessionEnumerator);
sessionEnumerator.GetCount(out int count);
// search for an audio session with the required name
// NOTE: we could also use the process id instead of the app name (with IAudioSessionControl2)
ISimpleAudioVolume volumeControl = null;
for (int i = 0; i < count; i++)
{
sessionEnumerator.GetSession(i, out IAudioSessionControl2 ctl);
ctl.GetProcessId(out int cpid);
if (cpid == pid)
{
volumeControl = (ISimpleAudioVolume)ctl;
break;
}
Marshal.ReleaseComObject(ctl);
}
Marshal.ReleaseComObject(sessionEnumerator);
Marshal.ReleaseComObject(mgr);
return(volumeControl);
}
private static IAudioEndpointVolume GetMasterVolumeObject()
{
IMMDeviceEnumerator deviceEnumerator = null;
IMmDevice speakers = null;
try
{
deviceEnumerator = MmDeviceEnumeratorFactory.CreateInstance();
deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.ERender, ERole.EMultimedia, out speakers);
var IID_IAudioEndpointVolume = typeof(IAudioEndpointVolume).GUID;
object o;
speakers.Activate(ref IID_IAudioEndpointVolume, 0, IntPtr.Zero, out o);
IAudioEndpointVolume masterVol = (IAudioEndpointVolume)o;
return(masterVol);
}
finally
{
if (speakers != null)
{
Marshal.ReleaseComObject(speakers);
}
if (deviceEnumerator != null)
{
Marshal.ReleaseComObject(deviceEnumerator);
}
}
}
