Interface IAudioEffectsChangedNotificationClient (audioclient.h)

Uma interface de retorno de chamada permite que os aplicativos recebam notificações quando a lista de efeitos de áudio para o fluxo de áudio associado é alterada ou quando os recursos necessários para habilitar um efeito são alterados, ou seja, quando o valor do campo canSetState do AUDIO_EFFECT associado é alterado.

Herança

A interface IAudioEffectsChangedNotificationClient herda da interface IUnknown.

Métodos

A interface IAudioEffectsChangedNotificationClient tem esses métodos.

IAudioEffectsChangedNotificationClient::OnAudioEffectsChanged Chamado pelo sistema quando a lista de efeitos de áudio é alterada ou os recursos necessários para habilitar um efeito são alterados.

Comentários

Registre a interface de retorno de chamada chamando IAudioEffectsManager::RegisterAudioEffectsChangedNotificationCallback.

Exemplos

O exemplo de código a seguir demonstra uma classe que implementa IAudioEffectsChangedNotificationClient para receber notificações quando a lista de efeitos de áudio é alterada ou os recursos necessários para habilitar alterações de efeito. No retorno de chamada OnAudioStreamEffectsChanged , o exemplo chama GetAudioEffects para obter a lista atual de efeitos.

class AudioEffectsChangedHandler :
    public winrt::implements<AudioEffectsChangedHandler, IAudioEffectsChangedNotificationClient>
{

    public:
    AudioEffectsChangedHandler(_In_ IAudioClient *client) : m_client(client){}
    STDMETHOD(OnAudioEffectsChanged)()
    {
        OnAudioStreamEffectsChanged(m_client.get());
        return S_OK;
    }
    private:
    wil::com_ptr_nothrow<IAudioClient> m_client;

};

wil::com_ptr_nothrow<IAudioEffectsChangedNotificationClient> g_effectsChangedHandler;

HRESULT RegisterAudioStreamEffectsChangedEvent(_In_ IAudioClient *client)
{
    if (!g_effectsChangedHandler)
    {
        wil::com_ptr_nothrow<IAudioEffectsManager> audioEffectsManager;
        RETURN_IF_FAILED(client->GetService(IID_PPV_ARGS(&audioEffectsManager)));

        // Register for the audio effects changed notification
        g_effectsChangedHandler = winrt::make<AudioEffectsChangedHandler>(client).get();
        RETURN_IF_NULL_ALLOC(g_effectsChangedHandler);

        return audioEffectsManager->RegisterAudioEffectsChangedNotificationCallback(
            g_effectsChangedHandler.get());
    }
    return S_OK;
}

HRESULT UnregisterAudioStreamEffectsChangedEvent(_In_ IAudioClient *client)
{
    if (g_effectsChangedHandler != nullptr)
    {
        wil::com_ptr_nothrow<IAudioEffectsManager> audioEffectsManager;
        RETURN_IF_FAILED(client->GetService(IID_PPV_ARGS(&audioEffectsManager)));

        // Unregister from the audio effects changed notification 
        return audioEffectsManager->UnregisterAudioEffectsChangedNotificationCallback(
            g_effectsChangedHandler.get());
        }

        return S_OK;
}

HRESULT OnAudioStreamEffectsChanged(_In_ IAudioClient *client)
{
    // Re-query the list of effects since there was some change
    wil::com_ptr_nothrow<IAudioEffectsManager> audioEffectsManager;
    RETURN_IF_FAILED(client->GetService(IID_PPV_ARGS(&audioEffectsManager)));
    wil::unique_cotaskmem_array_ptr<AUDIO_EFFECT> effects;
    UINT32 numEffects;
    RETURN_IF_FAILED(audioEffectsManager->GetAudioEffects(&effects, &numEffects));

    for (UINT32 i = 0; i < numEffects; i++)
    {

        // Here the app can check which effects are still enabled, and check if there are new
        // effects that now can be enabled.
        // As an example, the following code enables any effect that can be enabled, if it is not
        // already enabled.
        if (effects[i].canSetState && effects[i].state == AUDIO_EFFECT_STATE_OFF)
        {
            HRESULT hr = audioEffectsManager->SetAudioEffectState(effects[i].id, AUDIO_EFFECT_STATE_ON));
            if (hr == AUDCLNT_E_EFFECT_NOT_AVAILABLE || hr == AUDCLNT_E_EFFECT_STATE_READ_ONLY)
            {
                hr = S_OK;
            }
            RETURN_IF_FAILED(hr);

        }
    }

    return S_OK;
}

Requisitos

Requisito	Valor
Cliente mínimo com suporte	Windows Build 22000
Cabeçalho	audioclient.h

Confira também

AUDIO_EFFECT

IAudioEffectsManager::RegisterAudioEffectsChangedNotificationCallback