IMMDeviceEnumerator 如何获取音频设备的名称

#include <MMSystem.h>
#include <mmdeviceapi.h>
#include <endpointvolume.h>
#include <Functiondiscoverykeys_devpkey.h>//PKEY_Device_FriendlyName
//以下代码来自MSDN
#define EXIT_ON_ERROR(hres)  \
              if (FAILED(hres)) { goto Exit; }
#define SAFE_RELEASE(punk)  \
              if ((punk) != NULL)  \
                { (punk)->Release(); (punk) = NULL; }

const CLSID CLSID_MMDeviceEnumerator = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator = __uuidof(IMMDeviceEnumerator);

void PrintEndpointNames()
{
    HRESULT hr = S_OK;
    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDeviceCollection *pCollection = NULL;
    IMMDevice *pEndpoint = NULL;
    IPropertyStore *pProps = NULL;
    LPWSTR pwszID = NULL;

    hr = CoCreateInstance(
           CLSID_MMDeviceEnumerator, NULL,
           CLSCTX_ALL, IID_IMMDeviceEnumerator,
           (void**)&pEnumerator);
    EXIT_ON_ERROR(hr)

    hr = pEnumerator->EnumAudioEndpoints(
                        eRender, DEVICE_STATE_ACTIVE,
                        &pCollection);
    EXIT_ON_ERROR(hr)

    UINT  count;
    hr = pCollection->GetCount(&count);
    EXIT_ON_ERROR(hr)

    if (count == 0)
    {
        printf("No endpoints found.\n");
    }

    // Each loop prints the name of an endpoint device.
    for (ULONG i = 0; i < count; i++)
    {
        // Get pointer to endpoint number i.
        hr = pCollection->Item(i, &pEndpoint);
        EXIT_ON_ERROR(hr)

        // Get the endpoint ID string.
        hr = pEndpoint->GetId(&pwszID);
        EXIT_ON_ERROR(hr)
        
        hr = pEndpoint->OpenPropertyStore(
                          STGM_READ, &pProps);
        EXIT_ON_ERROR(hr)

        PROPVARIANT varName;
        // Initialize container for property value.
        PropVariantInit(&varName);

        // Get the endpoint's friendly-name property.
        hr = pProps->GetValue(
                       PKEY_Device_FriendlyName, &varName);//此处可以获得设备名称
        EXIT_ON_ERROR(hr)

        // Print endpoint friendly name and endpoint ID.
        printf("Endpoint %d: \"%S\" (%S)\n",
               i, varName.pwszVal, pwszID);

        CoTaskMemFree(pwszID);
        pwszID = NULL;
        PropVariantClear(&varName);
        SAFE_RELEASE(pProps)
        SAFE_RELEASE(pEndpoint)
    }
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pCollection)
    return;

Exit:
    printf("Error!\n");
    CoTaskMemFree(pwszID);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pCollection)
    SAFE_RELEASE(pEndpoint)
    SAFE_RELEASE(pProps)
}