AudioSessionState enumeration (audiosessiontypes.h)

The AudioSessionState enumeration defines constants that indicate the current state of an audio session.

Syntax

typedef enum _AudioSessionState {
  AudioSessionStateInactive,
  AudioSessionStateActive,
  AudioSessionStateExpired
} AudioSessionState;

Constants

Remarks

When a client opens a session by assigning the first stream to the session (by calling the IAudioClient::Initialize method), the initial session state is inactive. The session state changes from inactive to active when a stream in the session begins running (because the client has called the IAudioClient::Start method). The session changes from active to inactive when the client stops the last running stream in the session (by calling the IAudioClient::Stop method). The session state changes to expired when the client destroys the last stream in the session by releasing all references to the stream object.

The system volume-control program, Sndvol, displays volume controls for both active and inactive sessions. Sndvol stops displaying the volume control for a session when the session state changes to expired. For more information about Sndvol, see Audio Sessions.

The IAudioSessionControl::GetState and IAudioSessionEvents::OnStateChanged methods use the constants defined in the AudioSessionState enumeration.

For more information about session states, see Audio Sessions.

Requirements

See also

Core Audio Constants

Core Audio Enumerations

IAudioClient::Initialize

IAudioClient::Start

IAudioClient::Stop

IAudioSessionControl::GetState

IAudioSessionEvents::OnStateChanged