IAudioSessionControl::GetGroupingParam method (audiopolicy.h)
The GetGroupingParam method retrieves the grouping parameter of the audio session.
Syntax
HRESULT GetGroupingParam(
[out] GUID *pRetVal
);
Parameters
[out] pRetVal
Output pointer for the grouping-parameter GUID. This parameter must be a valid, non-NULL pointer to a caller-allocated GUID variable. The method writes the grouping parameter into this variable.
Return value
If the method succeeds, it returns S_OK. If it fails, possible return codes include, but are not limited to, the values shown in the following table.
| Return code | Description |
|---|---|
|
Parameter pRetVal is NULL. |
|
The audio endpoint device has been unplugged, or the audio hardware or associated hardware resources have been reconfigured, disabled, removed, or otherwise made unavailable for use. |
|
The Windows audio service is not running. |
Remarks
All of the audio sessions that have the same grouping parameter value are under the control of the same volume-level slider in the system volume-control program, Sndvol. For more information, see Grouping Parameters.
A client can call the IAudioSessionControl::SetGroupingParam method to change the grouping parameter of a session.
If a client has never called SetGroupingParam to assign a grouping parameter to an audio session, the session's grouping parameter value is GUID_NULL by default and a call to GetGroupingParam retrieves this value. A grouping parameter value of GUID_NULL indicates that the session does not belong to any grouping. In that case, the session has its own volume-level slider in the Sndvol program.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista [desktop apps | UWP apps] |
| Minimum supported server | Windows Server 2008 [desktop apps | UWP apps] |
| Target Platform | Windows |
| Header | audiopolicy.h |