如何在Windows中获取和设置系统卷

Question

我想在键盘上单击使用单位和c#将操作系统音量设置为某个级别,例如我想将Windows音量(不是统一)设置为70:我该怎么做？

void Update()
{   
    if (Input.GetKeyDown(KeyCode.A))
    {
        //Set Windows Volume 70%      
    }
}

Answer 1

这需要一个插件.由于这个问题适用于Windows,您可以使用IAudioEndpointVolume构建C++插件然后从C#调用它.这篇文章有一个有关如何更改卷的C++示例,IAudioEndpointVolume您可以将其用作创建C++插件的基本源.

我已经继续清理该代码然后转换为dll插件并将DLL放在Assets/Plugins文件夹中.您可以在此处了解如何构建C++插件.

C++代码:

#include "stdafx.h"
#include <windows.h>
#include <mmdeviceapi.h>
#include <endpointvolume.h>

#define DLLExport __declspec(dllexport)

extern "C"
{
    enum class VolumeUnit {
        Decibel,
        Scalar
    };

    //Gets volume
    DLLExport float GetSystemVolume(VolumeUnit vUnit) {
        HRESULT hr;

        // -------------------------
        CoInitialize(NULL);
        IMMDeviceEnumerator *deviceEnumerator = NULL;
        hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_INPROC_SERVER, __uuidof(IMMDeviceEnumerator), (LPVOID *)&deviceEnumerator);
        IMMDevice *defaultDevice = NULL;

        hr = deviceEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &defaultDevice);
        deviceEnumerator->Release();
        deviceEnumerator = NULL;

        IAudioEndpointVolume *endpointVolume = NULL;
        hr = defaultDevice->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&endpointVolume);
        defaultDevice->Release();
        defaultDevice = NULL;

        float currentVolume = 0;
        if (vUnit == VolumeUnit::Decibel) {
            //Current volume in dB
            hr = endpointVolume->GetMasterVolumeLevel(&currentVolume);
        }

        else if (vUnit == VolumeUnit::Scalar) {
            //Current volume as a scalar
            hr = endpointVolume->GetMasterVolumeLevelScalar(&currentVolume);
        }
        endpointVolume->Release();
        CoUninitialize();

        return currentVolume;
    }

    //Sets volume
    DLLExport void SetSystemVolume(double newVolume, VolumeUnit vUnit) {
        HRESULT hr;

        // -------------------------
        CoInitialize(NULL);
        IMMDeviceEnumerator *deviceEnumerator = NULL;
        hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_INPROC_SERVER, __uuidof(IMMDeviceEnumerator), (LPVOID *)&deviceEnumerator);
        IMMDevice *defaultDevice = NULL;

        hr = deviceEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &defaultDevice);
        deviceEnumerator->Release();
        deviceEnumerator = NULL;

        IAudioEndpointVolume *endpointVolume = NULL;
        hr = defaultDevice->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&endpointVolume);
        defaultDevice->Release();
        defaultDevice = NULL;

        if (vUnit == VolumeUnit::Decibel)
            hr = endpointVolume->SetMasterVolumeLevel((float)newVolume, NULL);

        else    if (vUnit == VolumeUnit::Scalar)
            hr = endpointVolume->SetMasterVolumeLevelScalar((float)newVolume, NULL);

        endpointVolume->Release();

        CoUninitialize();
    }
}

C#代码:

using System.Runtime.InteropServices;
using UnityEngine;

public class VolumeManager : MonoBehaviour
{
    //The Unit to use when getting and setting the volume
    public enum VolumeUnit
    {
        //Perform volume action in decibels</param>
        Decibel,
        //Perform volume action in scalar
        Scalar
    }

    /// <summary>
    /// Gets the current volume
    /// </summary>
    /// <param name="vUnit">The unit to report the current volume in</param>
    [DllImport("ChangeVolumeWindows")]
    public static extern float GetSystemVolume(VolumeUnit vUnit);
    /// <summary>
    /// sets the current volume
    /// </summary>
    /// <param name="newVolume">The new volume to set</param>
    /// <param name="vUnit">The unit to set the current volume in</param>
    [DllImport("ChangeVolumeWindows")]
    public static extern void SetSystemVolume(double newVolume, VolumeUnit vUnit);

    // Use this for initialization
    void Start()
    {
        //Get volume in Decibel 
        float volumeDecibel = GetSystemVolume(VolumeUnit.Decibel);
        Debug.Log("Volume in Decibel: " + volumeDecibel);

        //Get volume in Scalar 
        float volumeScalar = GetSystemVolume(VolumeUnit.Scalar);
        Debug.Log("Volume in Scalar: " + volumeScalar);

        //Set volume in Decibel 
        SetSystemVolume(-16f, VolumeUnit.Decibel);

        //Set volume in Scalar 
        SetSystemVolume(0.70f, VolumeUnit.Scalar);
    }
}

该GetSystemVolume函数用于获取当前音量并SetSystemVolume用于设置它.这个问题适用于Windows,但您可以使用其他平台的API执行类似的操作.

要70%在按下A键时将其设置为:

void Update()
{
    if (Input.GetKeyDown(KeyCode.A))
    {
        //Set Windows Volume 70%  
        SetSystemVolume(0.70f, VolumeUnit.Scalar);
    }
}