audio - 使用NAudio接收状态更改的 Audio Session 回调

Question

我想在音频 session 以NAudio开始和结束时接收回调。以下代码正在运行:

    private void SetupMediaSessionCallbacks()
    {
        // Foreach output endpoint
        foreach (var md in new MMDeviceEnumerator().EnumerateAudioEndPoints(DataFlow.Render, DeviceState.Active))
        {
            md.AudioSessionManager.OnSessionCreated += OnSessionCreated;
        }
    }

创建新的音频 session 时，将触发此代码。我是NAudio的新手，所以我不了解如何设置RegisterEventClient来接收状态更改事件:

    private void OnSessionCreated(object sender, IAudioSessionControl newSession)
    {
        // Not working, need help here!
        AudioSessionControl audioSession = new AudioSessionControl(newSession);
        IAudioSessionEventsHandler handler = null;
        AudioSessionEventsCallback notifications = new AudioSessionEventsCallback(test);
        handler.OnStateChanged += new EventHandler<AudioSessionState>(notifications_StateChanged);
        audioSession.RegisterEventClient(handler);
    }

这是回调，我认为是正确的:

    void notifications_StateChanged(object sender, AudioSessionState newState)
    {
        if (newState == AudioSessionState.AudioSessionStateActive)
        {
            Console.WriteLine("StateChanged");
        }
    }

任何帮助将不胜感激。我一直在搜索有关此问题的文档。

Answer 1

弄清楚了。我需要创建自己的类，该类继承自IAudioSessionEventsHandler。这是OnSessionCreated的代码:

private void OnSessionCreated(object sender, IAudioSessionControl newSession)
{
    AudioSessionControl audioSession = new AudioSessionControl(newSession);
    NAudioEventCallbacks callbacks = new NAudioEventCallbacks();
    AudioSessionEventsCallback notifications = new AudioSessionEventsCallback(callbacks);
    audioSession.RegisterEventClient(callbacks);

}

public class NAudioEventCallbacks : IAudioSessionEventsHandler
{
    public void OnChannelVolumeChanged(uint channelCount, IntPtr newVolumes, uint channelIndex) { }

    public void OnDisplayNameChanged(string displayName) { }

    public void OnGroupingParamChanged(ref Guid groupingId) { }

    public void OnIconPathChanged(string iconPath) { }

    public void OnSessionDisconnected(AudioSessionDisconnectReason disconnectReason) { }

    public void OnStateChanged(AudioSessionState state) { }

    public void OnVolumeChanged(float volume, bool isMuted) { }
}

现在，我可以在NAudioEventCallbacks中设置可以正常工作的断点。