> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AudioStateMonitorCallback

> AudioStateMonitorCallback

# AudioStateMonitorCallback

通过调用 [IAudioStateMonitor::RegisterCallback](https://devdocs.xbox.com/zh-CN/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md) 注册的回调函数;当与 [IAudioStateMonitor](https://devdocs.xbox.com/zh-CN/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor.md) 关联的音频流的音量级别发生变化时,系统会调用该函数。

## Syntax

```cpp theme={null}
void CALLBACK AudioStateMonitorCallback(
  IAudioStateMonitor *audioStateMonitor,
  void *context
);
```

### Parameters

*audioStateMonitor* \_Out\_\
Type: IAudioStateMonitor\*

注册回调所针对的 [IAudioStateMonitor](https://devdocs.xbox.com/zh-CN/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor.md) 接口。调用该接口的 [GetSoundLevel](https://devdocs.xbox.com/zh-CN/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-getsoundlevel.md) 方法可获取所关联音频流的最新当前音量级别。

*context*\
Type: void\*

传入 `RegisterCallback` 方法的应用定义上下文对象。

### Return value

此回调函数不返回值。

## Remarks

为方便起见,Audiostatemonitorapi.h 将此回调的指针类型定义为 **PAudioStateMonitorCallback**。

以下代码示例演示如何向 `AudioStateMonitor` 注册新的回调。为方便起见,*Audiostatemonitorapi.h* 将此回调的指针类型定义为 `PAudioStateMonitorCallback`。

```cpp theme={null}
// Registers a new callback with the AudioStateMonitor.

    STDMETHOD(RegisterCallback) (_In_ PAudioStateMonitorCallback callback, _In_opt_ void* context, _Out_ AudioStateMonitorRegistrationHandle* registration) PURE;
```

## Requirements

**头文件:** Audiostatemonitorapi.h

**支持的平台:** Windows、XBOX One 系列主机和 XBOX Series 主机

## See also

[AUDIO\_STREAM\_CATEGORY](https://learn.microsoft.com/windows/win32/api/audiosessiontypes/ne-audiosessiontypes-audio_stream_category)

[关于 WASAPI](https://learn.microsoft.com/windows/desktop/CoreAudio/wasapi)

[WASAPI](https://devdocs.xbox.com/zh-CN/build/console-features/audio/overviews/wasapi-overview.md)


## Related topics

- [IAudioStateMonitor::RegisterCallback method](https://devdocs.xbox.com/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md)
- [Méthode IAudioStateMonitor::RegisterCallback](https://devdocs.xbox.com/fr-CA/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md)
- [IAudioStateMonitor::RegisterCallback, méthode](https://devdocs.xbox.com/fr/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md)
- [Método IAudioStateMonitor::RegisterCallback](https://devdocs.xbox.com/pt-BR/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md)
- [IAudioStateMonitor::RegisterCallback 方法](https://devdocs.xbox.com/zh-CN/reference/audio/audiostatemonitor/interfaces/iaudiostatemonitor-registercallback.md)