IDirectMusicSynth::Activate method (dmusics.h)

發行項
12/05/2018

The Activate method enables or disables the audio device under program control.

Syntax

HRESULT Activate(
  BOOL fEnable
);

Parameters

fEnable

Specifies whether to enable or disable the audio device. If TRUE, the method enables the device. If FALSE, the method disables it.

Return value

Activate returns S_OK if the call was successful. Otherwise, the method returns an appropriate error code. The following table shows some of the possible return status codes.

Return code	Description
S_FALSE	Indicates audio device is already inactive.
E_FAIL	Indicates that the request failed.
E_OUTOFMEMORY	Indicates that not enough memory is available to load the device.
DMUS_E_SYNTHNOTCONFIGURED	Indicates that the synth is not opened or not properly configured.
DMUS_E_NOSYNTHSINK	Indicates that the IDirectMusicSynthSink object was not connected.
DMUS_E_SYNTHACTIVE	Indicates that the synth is already active.

Remarks

By enabling or disabling the audio device under program control, Activate gives the application the ability to manage its use of resources. When not playing music, the application can deactivate the wave-output resource, which frees it for other applications to use.

The wave-output resource is actually managed by a separate COM object, which has a IDirectMusicSynthSink interface. This object must first be connected with a call to SetSynthSink. Otherwise, the synthesizer will fail the Activate call with DMUS_E_NOSYNTHSINK.

Activation is mostly managed by the wave sink object. When IDirectMusicSynth::Activate is called, the synth sets its internal activation state and calls IDirectMusicSynthSink::Activate to enable or disable the wave output.

Requirements


Target Platform	Desktop
Header	dmusics.h (include Dmusics.h)