#include <windows.h>

#include <mmdeviceapi.h>

#include <endpointvolume.h>

#include <audioclient.h>

//参数:

//    -2 恢复静音

//    -1 静音

//    0~100:音量比例

bool SetVolumeLevel(int level)

{

    HRESULT hr;

    IMMDeviceEnumerator* pDeviceEnumerator=;

    IMMDevice* pDevice=;

    IAudioEndpointVolume* pAudioEndpointVolume=;

    IAudioClient* pAudioClient=;

    try{

        hr = CoCreateInstance(__uuidof(MMDeviceEnumerator),NULL,CLSCTX_ALL,__uuidof(IMMDeviceEnumerator),(void**)&pDeviceEnumerator);

        if(FAILED(hr)) throw "CoCreateInstance";

        hr = pDeviceEnumerator->GetDefaultAudioEndpoint(eRender,eMultimedia,&pDevice);

        if(FAILED(hr)) throw "GetDefaultAudioEndpoint";

        hr = pDevice->Activate(__uuidof(IAudioEndpointVolume),CLSCTX_ALL,NULL,(void**)&pAudioEndpointVolume);

        if(FAILED(hr)) throw "pDevice->Active";

        hr = pDevice->Activate(__uuidof(IAudioClient),CLSCTX_ALL,NULL,(void**)&pAudioClient);

        if(FAILED(hr)) throw "pDevice->Active";

        if(level==-){

            hr = pAudioEndpointVolume->SetMute(FALSE,NULL);

            if(FAILED(hr)) throw "SetMute";

        }else if(level==-){

            hr = pAudioEndpointVolume->SetMute(TRUE,NULL);

            if(FAILED(hr)) throw "SetMute";

        }else{

            if(level< || level>){

                hr = E_INVALIDARG;

                throw "Invalid Arg";

            }

            float fVolume;

            fVolume = level/100.0f;

            hr = pAudioEndpointVolume->SetMasterVolumeLevelScalar(fVolume,&GUID_NULL);

            if(FAILED(hr)) throw "SetMasterVolumeLevelScalar";

            pAudioClient->Release();

            pAudioEndpointVolume->Release();

            pDevice->Release();

            pDeviceEnumerator->Release();

            return true;

        }

    }

    catch(...){

        if(pAudioClient) pAudioClient->Release();

        if(pAudioEndpointVolume) pAudioEndpointVolume->Release();

        if(pDevice) pDevice->Release();

        if(pDeviceEnumerator) pDeviceEnumerator->Release();

        throw;

    }

    return false;

}

int main()

{

    CoInitialize();

    try{

        //3秒后静音

        Sleep();

        SetVolumeLevel(-);

        //3秒后恢复静音

        Sleep();

        SetVolumeLevel(-);

        //调节音量

        Sleep();

        SetVolumeLevel();

        Sleep();

        SetVolumeLevel();

        Sleep();

        SetVolumeLevel();

    }

    catch(...){

        //错误处理...

    }

    CoUninitialize();

    return ;

}