IDirectSound::SetCooperativeLevel

HRESULT SetCooperativeLevel(HWND hwnd, DWORD dwLevel);

Sets the cooperative level of the application for this sound device.

·Returns DS_OK if successful, or one of the following error values otherwise:

DSERR_ALLOCATED

DSERR_INVALIDPARAM

DSERR_UNINITIALIZED

DSERR_UNSUPPORTED

hwnd

Window handle for the application.

dwLevel

Requested priority level. Specify one of the following values:

DSSCL_EXCLUSIVE

Sets the application to the exclusive level. When it has the input focus, the application will be the only one audible (sounds from applications with the DSBCAPS_GLOBALFOCUS flag set will be muted). With this level, it also has all the privileges of the DSSCL_PRIORITY level. DirectSound will restore the hardware format, as specified by the most recent call to the IDirectSoundBuffer::SetFormat method, once the application gains the input focus. (Note that DirectSound will always restore the wave format no matter what priority level is set.)

DSSCL_NORMAL

Sets the application to a fully cooperative status. Most applications should use this level, because it has the smoothest multitasking and resource-sharing behavior.

DSSCL_PRIORITY

Sets the application to the priority level. Applications with this cooperative level can call the IDirectSoundBuffer::SetFormat and IDirectSound::Compact methods.

DSSCL_WRITEPRIMARY

This is the highest priority level. The application has write access to the primary sound buffers. No secondary sound buffers in any application can be played.

The application must set the cooperative level by calling this method before its buffers can be played. The recommended cooperative level is DSSCL_NORMAL; use other priority levels when necessary. For additional information, see Cooperative Levels.