在Vista / 7上获取音量变化通知（C ++）

Question

我试图在Windows Vista / 7上每当主卷更改时收到通知。这是我正在使用的代码：

#include <audiopolicy.h>
#include <audioclient.h>
#include <mmdeviceapi.h>
#include <endpointvolume.h>
#include <windows.h>
#include <shlwapi.h>
#include <iostream>
#include <Tchar.h>

static const GUID AudioSessionVolumeCtx = { 0x2715279f, 0x4139, 0x4ba0, { 0x9c, 0xb1, 0xb3, 0x51, 0xf1, 0xb5, 0x8a, 0x4a } };

template <class T> void SafeRelease(T **ppT)
{
    if (*ppT)
    {
        (*ppT)->Release();
        *ppT = NULL;
    }
}

class CAudioSessionVolume : public IAudioSessionEvents
{
public:
    static HRESULT CreateInstance( UINT uNotificationMessage, HWND hwndNotification, CAudioSessionVolume **ppAudioSessionVolume )
    {
        CAudioSessionVolume *pAudioSessionVolume = new (std::nothrow) 
            CAudioSessionVolume(uNotificationMessage, hwndNotification);

        if (pAudioSessionVolume == NULL)
        {
            return E_OUTOFMEMORY;
        }

        HRESULT hr = pAudioSessionVolume->Initialize();
        if (SUCCEEDED(hr))
        {
            *ppAudioSessionVolume = pAudioSessionVolume;
        }
        else
        {
            pAudioSessionVolume->Release();
        }

        return hr;
    }

    // IUnknown methods.
    STDMETHODIMP QueryInterface(REFIID riid, void **ppv)
    {
        static const QITAB qit[] = 
        {
            QITABENT(CAudioSessionVolume, IAudioSessionEvents),
            { 0 },
        };
        return QISearch(this, qit, riid, ppv);
    }

    STDMETHODIMP_(ULONG) AddRef()
    {
        return InterlockedIncrement(&m_cRef);
    }

    STDMETHODIMP_(ULONG) Release()
    {
        LONG cRef = InterlockedDecrement( &m_cRef );
        if (cRef == 0)
        {
            delete this;
        }
        return cRef;
    }

    STDMETHODIMP OnSimpleVolumeChanged( float NewVolume, BOOL NewMute, LPCGUID EventContext )
    {
        MessageBox(NULL, _T("vol changed"), _T("test"), MB_OK);
        return S_OK;
    }

    // The remaining audio session events do not require any action.
    STDMETHODIMP OnDisplayNameChanged(LPCWSTR,LPCGUID)
    {
        return S_OK;
    }

    STDMETHODIMP OnIconPathChanged(LPCWSTR,LPCGUID)
    {
        return S_OK;
    }

    STDMETHODIMP OnChannelVolumeChanged(DWORD,float[],DWORD,LPCGUID)
    {
        return S_OK;
    }

    STDMETHODIMP OnGroupingParamChanged(LPCGUID,LPCGUID)
    {
        return S_OK;
    }

    STDMETHODIMP OnStateChanged(AudioSessionState)
    {
        return S_OK;
    }

    STDMETHODIMP OnSessionDisconnected(AudioSessionDisconnectReason)
    {
        return S_OK;
    }

    // Other methods
    HRESULT EnableNotifications(BOOL bEnable)
    {
        HRESULT hr = S_OK;

        if (bEnable)
        {
            hr = m_pAudioSession->RegisterAudioSessionNotification(this);
        }
        else
        {
            hr = m_pAudioSession->UnregisterAudioSessionNotification(this);
        }

        return hr;
    }

    HRESULT SetDisplayName(const WCHAR *wszName)
    {
        if (m_pAudioSession == NULL)
        {
            return E_FAIL;
        }
        else
        {
            return m_pAudioSession->SetDisplayName(wszName, NULL);
        }
    }

protected:
    CAudioSessionVolume( UINT uNotificationMessage, HWND hwndNotification ) :
        m_cRef(1), m_pAudioSession(NULL), m_pSimpleAudioVolume(NULL)
    {
    }

    ~CAudioSessionVolume()
    {
        EnableNotifications(FALSE);

        SafeRelease(&m_pAudioSession);
        SafeRelease(&m_pSimpleAudioVolume);
    }

    HRESULT Initialize()
    {
        HRESULT hr = S_OK;

        IMMDeviceEnumerator *pDeviceEnumerator = NULL;
        IMMDevice *pDevice = NULL;
        IAudioSessionManager *pAudioSessionManager = NULL;

        // Get the enumerator for the audio endpoint devices.
        hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
            CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pDeviceEnumerator));

        if (FAILED(hr)) 
        { 
            goto done; 
        }

        // Get the default audio endpoint that the SAR will use.
        hr = pDeviceEnumerator->GetDefaultAudioEndpoint(eRender, eConsole,
            &pDevice);

        if (FAILED(hr)) 
        { 
            goto done; 
        }

        // Get the session manager for this device.
        hr = pDevice->Activate(__uuidof(IAudioSessionManager), 
            CLSCTX_INPROC_SERVER, NULL, (void**) &pAudioSessionManager);

        if (FAILED(hr)) 
        { 
            goto done; 
        }

        // Get the audio session. 
        hr = pAudioSessionManager->GetAudioSessionControl( 
            &GUID_NULL,     // Get the default audio session. 
            FALSE,          // The session is not cross-process.
            &m_pAudioSession);


        if (FAILED(hr)) 
        { 
            goto done; 
        }

        hr = pAudioSessionManager->GetSimpleAudioVolume(&GUID_NULL, 0,
            &m_pSimpleAudioVolume);

    done:
        SafeRelease(&pDeviceEnumerator);
        SafeRelease(&pDevice);
        SafeRelease(&pAudioSessionManager);
        return hr;
    }

private:
    LONG m_cRef;

    IAudioSessionControl    *m_pAudioSession;
    ISimpleAudioVolume      *m_pSimpleAudioVolume;
};

int main()
{
    CoInitialize(NULL);
    CAudioSessionVolume *asv;
    CAudioSessionVolume::CreateInstance(0, NULL, &asv);
    asv->EnableNotifications(true);

    char s;
    gets(&s);
}

当系统音量发生变化时，我期待得到一个消息框说“vol changed”，但我从未收到消息框。

我从http://msdn.microsoft.com/en-us/library/dd374921(VS.85).aspx

获得了大部分代码

我做错了什么？

编辑：我在更改应用程序的卷时收到通知（感谢@nobugz）。但是在更改主音量时我想要通知。 （在Win7的“音量混合器”对话框中列为“设备”）

编辑2： Larry Osterman有一系列有关Vista / 7中音量的博客文章。这个特别有意思：http://blogs.msdn.com/larryosterman/archive/2007/03/22/fun-with-the-endpoint-volume-interfaces-closing-the-loop.aspx我明天会尝试代码，看看能不能得到我想要的东西。现在是时候睡觉了。

编辑3：这是Larry博客文章中的完整代码，包括上面发布的链接。它做我需要的，然后做一些。我会尝试修剪我不需要的功能。

#include <windows.h>
#include <mmdeviceapi.h>
#include <endpointvolume.h>
#include <Tchar.h>
#include <strsafe.h>

class CVolumeNotification : public IAudioEndpointVolumeCallback 
{ 
    LONG m_RefCount; 
    ~CVolumeNotification(void) {}; 
public: 
    CVolumeNotification(void) : m_RefCount(1) 
    { 
    } 
    STDMETHODIMP_(ULONG)AddRef() { return InterlockedIncrement(&m_RefCount); } 
    STDMETHODIMP_(ULONG)Release()  
    { 
        LONG ref = InterlockedDecrement(&m_RefCount);  
        if (ref == 0) 
            delete this; 
        return ref; 
    } 
    STDMETHODIMP QueryInterface(REFIID IID, void **ReturnValue) 
    { 
        if (IID == IID_IUnknown || IID== __uuidof(IAudioEndpointVolumeCallback))  
        { 
            *ReturnValue = static_cast<IUnknown*>(this); 
            AddRef(); 
            return S_OK; 
        } 
        *ReturnValue = NULL; 
        return E_NOINTERFACE; 
    } 

    STDMETHODIMP OnNotify(PAUDIO_VOLUME_NOTIFICATION_DATA NotificationData) 
    { 
        wchar_t outputString[256]; 
        DWORD written; 
        COORD writeCoord; 
        StringCbPrintf(outputString, sizeof(outputString), L"Volume Changed: %f", NotificationData->fMasterVolume); 

        writeCoord.X = 0; 
        writeCoord.Y = 3; 
        WriteConsoleOutputCharacter(GetStdHandle(STD_OUTPUT_HANDLE), outputString, (DWORD)wcslen(outputString), writeCoord, &written); 
        return S_OK; 
    } 
}; 

struct TimerContext 
{ 
    IAudioMeterInformation *_Meter; 
}; 

const int TimerPeriodicityMS = 100; 
void CALLBACK TimerMeterCallback(PTP_CALLBACK_INSTANCE CallbackInstance, PVOID Context, PTP_TIMER Timer) 
{
    TimerContext *timerContext = (TimerContext *)Context; 
    wchar_t outputString[256]; 
    float peakValue; 
    DWORD written; 
    COORD writeCoord; 
    StringCbCopy(outputString, sizeof(outputString), L"Meter: "); 

    timerContext->_Meter->GetPeakValue(&peakValue); 
    for (size_t i = 0 ; i < peakValue*100; i += 1) 
    { 
        StringCbCat(outputString, sizeof(outputString), L"*"); 
    } 
    for (size_t i = (size_t)(peakValue*100) ; i < 100; i += 1) 
    { 
        StringCbCat(outputString, sizeof(outputString), L"."); 
    } 
    writeCoord.X = 0; 
    writeCoord.Y = 1; 
    WriteConsoleOutputCharacter(GetStdHandle(STD_OUTPUT_HANDLE), outputString, (DWORD)wcslen(outputString), writeCoord, &written); 
} 

int _tmain(int argc, _TCHAR* argv[])
{
    CoInitialize(NULL);
    HRESULT hr;
    IMMDeviceEnumerator *deviceEnumerator = NULL;;
    HANDLE handle; 
    TP_CALLBACK_ENVIRON callbackEnvironment; 
    PTP_CLEANUP_GROUP cleanupGroup; 
    PTP_TIMER timer; 
    TimerContext context; 

    InitializeThreadpoolEnvironment(&callbackEnvironment); 
    cleanupGroup = CreateThreadpoolCleanupGroup(); 
    SetThreadpoolCallbackCleanupGroup(&callbackEnvironment, cleanupGroup, NULL); 

    timer = CreateThreadpoolTimer(TimerMeterCallback, &context, &callbackEnvironment); 

    //
    //    Clear the screen.  Code stolen from: http://support.microsoft.com/kb/319257.
    //
    handle = GetStdHandle(STD_OUTPUT_HANDLE);
    DWORD writtenChars = 0;
    CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
    COORD home;
    home.X = home.Y = 0;
    GetConsoleScreenBufferInfo(handle, &consoleInfo);
    FillConsoleOutputCharacter(handle, L' ', consoleInfo.dwSize.X * consoleInfo.dwSize.Y, home, &writtenChars);
    SetConsoleCursorPosition(handle, home);

    //
    //    Set the console to raw mode. 
    //
    DWORD oldMode;
    GetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), &oldMode);
    SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), oldMode & ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT));

    // 
    //    Instantiate an endpoint volume object.
    //
    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);
    CVolumeNotification *volumeNotification = new CVolumeNotification(); 
    hr = endpointVolume->RegisterControlChangeNotify(volumeNotification); 
    hr = defaultDevice->Activate(__uuidof(IAudioMeterInformation), CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&context._Meter); 
    defaultDevice->Release(); 
    defaultDevice = NULL; 
    // Set a 100 millisecond timer. 
    LARGE_INTEGER timerPeriodicityLI; 
    FILETIME timerPeriodicity; 
    timerPeriodicityLI.QuadPart = -1*(TimerPeriodicityMS* 10000 ); 

    timerPeriodicity.dwLowDateTime = timerPeriodicityLI.LowPart; 
    timerPeriodicity.dwHighDateTime = timerPeriodicityLI.HighPart; 

    SetThreadpoolTimer(timer, &timerPeriodicity, TimerPeriodicityMS, 10); 

    wchar_t inputChar = '\0';
    while (inputChar != '\r')
    {
        UINT currentStep, stepCount;
        DWORD read, written;
        COORD writeCoord;
        wchar_t outputString[256];
        StringCbCopy(outputString, sizeof(outputString), L"Volume: ");

        // 
        //    Calculate the cheesy OSD.
        //
        endpointVolume->GetVolumeStepInfo(&currentStep, &stepCount);
        for (size_t i = 0 ; i < stepCount ; i += 1)
        {
            if (i <= currentStep)
            {
                StringCbCat(outputString, sizeof(outputString), L"=");
            }
            else
            {
                StringCbCat(outputString, sizeof(outputString), L"-");
            }
        }
        writeCoord.X = 0;
        writeCoord.Y = 0;
        WriteConsoleOutputCharacter(handle, outputString, (DWORD)wcslen(outputString), writeCoord, &written);

        ReadConsole(GetStdHandle(STD_INPUT_HANDLE), &inputChar, 1, &read, NULL);
        if (inputChar == '+')
        {
            endpointVolume->VolumeStepUp(NULL);
        }
        else if (inputChar == '-')
        {
            endpointVolume->VolumeStepDown(NULL);
        }
    }

    // 
    //    Remove our notification. 
    // 
    endpointVolume->UnregisterControlChangeNotify(volumeNotification); 

    endpointVolume->Release(); 
    volumeNotification->Release(); 
    SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), oldMode);

    CloseThreadpoolCleanupGroupMembers(cleanupGroup, FALSE, NULL); 
    CloseThreadpoolCleanupGroup(cleanupGroup); 
    cleanupGroup = NULL; 
    DestroyThreadpoolEnvironment(&callbackEnvironment); 

    context._Meter->Release(); 

    CoUninitialize();

    return 0;
}

编辑4：这是Larry代码的精简版。

#include <windows.h>
#include <mmdeviceapi.h>
#include <endpointvolume.h>
#include <iostream>
#include <Tchar.h>

class CVolumeNotification : public IAudioEndpointVolumeCallback 
{ 
    LONG m_RefCount; 
    ~CVolumeNotification(void) {}; 
public: 
    CVolumeNotification(void) : m_RefCount(1) 
    { 
    } 
    STDMETHODIMP_(ULONG)AddRef() { return InterlockedIncrement(&m_RefCount); } 
    STDMETHODIMP_(ULONG)Release()  
    { 
        LONG ref = InterlockedDecrement(&m_RefCount);  
        if (ref == 0) 
            delete this; 
        return ref; 
    } 
    STDMETHODIMP QueryInterface(REFIID IID, void **ReturnValue) 
    { 
        if (IID == IID_IUnknown || IID== __uuidof(IAudioEndpointVolumeCallback))  
        { 
            *ReturnValue = static_cast<IUnknown*>(this); 
            AddRef(); 
            return S_OK; 
        } 
        *ReturnValue = NULL; 
        return E_NOINTERFACE; 
    } 

    STDMETHODIMP OnNotify(PAUDIO_VOLUME_NOTIFICATION_DATA NotificationData) 
    { 
        std::cout << NotificationData->fMasterVolume << _T(" ");

        return S_OK; 
    } 
}; 

int _tmain(int argc, _TCHAR* argv[])
{
    CoInitialize(NULL);
    HRESULT hr;
    IMMDeviceEnumerator *deviceEnumerator = NULL;;

    // 
    //    Instantiate an endpoint volume object.
    //
    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);
    CVolumeNotification *volumeNotification = new CVolumeNotification(); 
    hr = endpointVolume->RegisterControlChangeNotify(volumeNotification); 
    defaultDevice->Release(); 
    defaultDevice = NULL; 

    wchar_t inputChar = '\0';
    while (inputChar != '\r')
    {
        DWORD read;
        ReadConsole(GetStdHandle(STD_INPUT_HANDLE), &inputChar, 1, &read, NULL);
    }

    // 
    //    Remove our notification. 
    // 
    endpointVolume->UnregisterControlChangeNotify(volumeNotification); 
    endpointVolume->Release(); 
    volumeNotification->Release(); 

    CoUninitialize();

    return 0;
}

我还没有看过SDK示例。我现在知道这些东西如何运行得足以将我需要的东西添加到我的应用程序中。感谢大家的帮助！

Answer 1

我尝试时效果很好。请务必单击音量控制托盘图标，单击混音器并修改您的应用的音量。

Answer 2

Windows SDK "OSD" sample是一个比我在博客上发布的更简单的监视硬件卷的例子（你不需要该帖子中的所有计量垃圾）。