关于Windows上声卡插拔检测

使用到什么：

mmdeviceapi.h   windows.h

1注册设备状态检测函数

RegisterEndpointNotificationCallback((IMMNotificationclient))

来源：https://blog.csdn.net/std4453/article/details/72902954

#define SAFE_RELEASE(punk)  \
 if ((punk) != NULL)  \
 { (punk)->Release(); (punk) = NULL; }   

#include <windows.h>
#include <setupapi.h>  
#include <initguid.h>
#include <mmdeviceapi.h>  
#include <Functiondiscoverykeys_devpkey.h>
#include "iostream"
#include <stdio.h>
using namespace std;    

class CMMNotificationClient : public IMMNotificationClient   
{   
public:  
    IMMDeviceEnumerator *m_pEnumerator;  
    CMMNotificationClient():  
    _cRef(1),  
    m_pEnumerator(NULL)  
    {  
        // 初始化COM  
        ::CoInitialize(NULL);  
        HRESULT hr = S_OK;   

        // 创建接口
        hr = CoCreateInstance(   
            __uuidof(MMDeviceEnumerator), NULL,   
            CLSCTX_ALL, __uuidof(IMMDeviceEnumerator),   
            (void**)&m_pEnumerator);   

        if (hr==S_OK)   
        {   
            cout<<"接口创建成功"<<endl;   
        }   
        else   
        {   
            cout<<"接口创建失败"<<endl;   
        }   

        // 注册事件
        hr = m_pEnumerator->RegisterEndpointNotificationCallback((IMMNotificationClient*)this);   
        if (hr==S_OK)
        {   
            cout<<"注册成功"<<endl;   
        }   
        else   
        {   
            cout<<"注册失败"<<endl;   
        }   
    }  

    ~CMMNotificationClient()  
    {  
        SAFE_RELEASE(m_pEnumerator)  
        ::CoUninitialize();   
    }  

    // IUnknown methods -- AddRef, Release, and QueryInterface   
private:  
    LONG _cRef;   

    // Private function to print device-friendly name
    HRESULT _PrintDeviceName(LPCWSTR  pwstrId);

    ULONG STDMETHODCALLTYPE AddRef()  
    {  
        return InterlockedIncrement(&_cRef);  
    }  

    ULONG STDMETHODCALLTYPE Release()  
    {  
        ULONG ulRef = InterlockedDecrement(&_cRef);  
        if (0 == ulRef)  
        {  
            delete this;  
        }  
        return ulRef;  
    }  

    HRESULT STDMETHODCALLTYPE QueryInterface(  
        REFIID riid, VOID **ppvInterface)  
    {  
        if (IID_IUnknown == riid)  
        {  
            AddRef();  
            *ppvInterface = (IUnknown*)this;  
        }  
        else if (__uuidof(IMMNotificationClient) == riid)  
        {  
            AddRef();  
            *ppvInterface = (IMMNotificationClient*)this;  
        }  
        else  
        {  
            *ppvInterface = NULL;  
            return E_NOINTERFACE;  
        }  
        return S_OK;  
    }  

    HRESULT STDMETHODCALLTYPE OnDefaultDeviceChanged(   
        EDataFlow flow, ERole role,   
        LPCWSTR pwstrDeviceId)   
    {   
        cout<<"OnDefaultDeviceChanged"<<endl;
        return S_OK;   
    }   

    HRESULT STDMETHODCALLTYPE OnDeviceAdded(LPCWSTR pwstrDeviceId)   
    {   
        cout<<"OnDeviceAdded"<<endl;
        return S_OK;   
    };   

    HRESULT STDMETHODCALLTYPE OnDeviceRemoved(LPCWSTR pwstrDeviceId)   
    {   
        cout<<"OnDeviceRemoved"<<endl;
        return S_OK;   
    }   

    HRESULT STDMETHODCALLTYPE OnDeviceStateChanged(   
        LPCWSTR pwstrDeviceId,   
        DWORD dwNewState)   
    {   
        cout<<"OnDeviceStateChanged"<<endl;
        return S_OK;   
    }   

    HRESULT STDMETHODCALLTYPE OnPropertyValueChanged(   
        LPCWSTR pwstrDeviceId,   
        const PROPERTYKEY key)   
    {   
        cout<<"OnPropertyValueChanged"<<endl;
        _PrintDeviceName(pwstrDeviceId);
        return S_OK;   
    }   
};   

// Given an endpoint ID string, print the friendly device name.
HRESULT CMMNotificationClient::_PrintDeviceName(LPCWSTR pwstrId)
{
    HRESULT hr = S_OK;
    IMMDevice *pDevice = NULL;
    IPropertyStore *pProps = NULL;
    PROPVARIANT varString;

    CoInitialize(NULL);
    PropVariantInit(&varString);

    if (m_pEnumerator == NULL)
    {
        // Get enumerator for audio endpoint devices.
        hr = CoCreateInstance(__uuidof(MMDeviceEnumerator),
                              NULL, CLSCTX_INPROC_SERVER,
                              __uuidof(IMMDeviceEnumerator),
                              (void**)&m_pEnumerator);
    }
    if (hr == S_OK)
    {
        hr = m_pEnumerator->GetDevice(pwstrId, &pDevice);
    }
    if (hr == S_OK)
    {
        hr = pDevice->OpenPropertyStore(STGM_READ, &pProps);
    }
    if (hr == S_OK)
    {
        // Get the endpoint device's friendly-name property.
        hr = pProps->GetValue(PKEY_Device_FriendlyName, &varString);
    }
    printf("----------------------\nDevice name: \"%S\"\n"
           "  Endpoint ID string: \"%S\"\n",
           (hr == S_OK) ? varString.pwszVal : L"null device",
           (pwstrId != NULL) ? pwstrId : L"null ID");

    PropVariantClear(&varString);

    SAFE_RELEASE(pProps)
    SAFE_RELEASE(pDevice)
    return hr;
}

int main(int argc, TCHAR* argv[], TCHAR* envp[])   
{   
    CMMNotificationClient mmClient;

    cin.get();
    return 0;   
}