编程调节Win7/Win8系统音量的一种方法

isgood

　　不得不说, 自Win7(好像是吧), Windows的音量调节功能比以前更人性化了....
     但编程接口却变得更加复杂了............. 还要用到IAudioEndpointVolume………….   
     下面的代码是我整理的, 经测试可用, 嫌麻烦的可以直接拿来用, 接口很简单, 因而只能整个系统的音量...   



#include  
#include  
#include
#include

//参数:
//    -2 恢复静音
//    -1 静音
//    0~100:音量比例
bool SetVolumeLevel(int level)
{
HRESULT hr;
IMMDeviceEnumerator* pDeviceEnumerator=0;
IMMDevice* pDevice=0;
IAudioEndpointVolume* pAudioEndpointVolume=0;
IAudioClient* pAudioClient=0;
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==-2){
hr = pAudioEndpointVolume->SetMute(FALSE,NULL);
if(FAILED(hr)) throw "SetMute";
}else if(level==-1){
hr = pAudioEndpointVolume->SetMute(TRUE,NULL);
if(FAILED(hr)) throw "SetMute";
}else{
if(level100){
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(0);
try{
//3秒后静音
Sleep(3000);
SetVolumeLevel(-1);
//3秒后恢复静音
Sleep(3000);
SetVolumeLevel(-2);
//调节音量
Sleep(3000);
SetVolumeLevel(10);
Sleep(3000);
SetVolumeLevel(30);
Sleep(3000);
SetVolumeLevel(20);
}
catch(...){
//错误处理...
    }
CoUninitialize();
return 0;
}
　　
　　下载:http://share.weiyun.com/19003dc8fd0804aaf1fc03b2430e832e
　　参考:
              IAudioEndpointVolume interface
              Win7/Vista Audio API Master Volume Control
               
　　女孩不哭 @ iyunv.com/memset @ 2014-04-07