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IDirectMusicSynth::Activate method (dmusics.h)

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

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

See also

IDirectMusicSynth::Open

IDirectMusicSynthSink::Activate