Question

我正在维护一个旧代码库，它使用waveOutGetDevCaps来获取系统上音频设备的名称。在Windows 7计算机上，这会导致名称被截断，因为WAVEOUTCAPS.szPname受MAXPNAMELEN（31个字符）的限制。

Win7的做法是什么？

Answer 1

您可以使用其中一个Core Audio API：

// get the device enumerator
IMMDeviceEnumerator* pEnumerator = NULL;
HRESULT hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
                              CLSCTX_ALL,__uuidof(IMMDeviceEnumerator),
                              (void**)&pEnumerator);

// get the endpoint collection
IMMDeviceCollection* pCollection = NULL;
DWORD mask = DEVICE_STATE_ACTIVE || DEVICE_STATE_UNPLUGGED;
hr = pEnumerator->EnumAudioEndpoints(eRender, mask, &pCollection);

// get the size of the collection
UINT count = 0;
hr = pCollection->GetCount(&count);

for (int i = 0; i < (int)count; i++)
{
    // get the endpoint
    IMMDevice* pEndPoint = NULL;
    hr = pCollection->Item(i, &pEndPoint);

    // get the human readable name
    String^ friendlyName;
    IPropertyStore* pProps = NULL;
    HRESULT hr = pEndPoint->OpenPropertyStore(STGM_READ, &pProps);
    PROPVARIANT varName;
    PropVariantInit(&varName);
    hr = pProps->GetValue(PKEY_Device_FriendlyName, &varName);
    friendlyName = gcnew String(varName.pwszVal);
    PropVariantClear(&varName);
}

在上面的代码中删除了错误处理，使其更具可读性。（我喜欢使用C ++ / CLI在C＃和Windows API之间移动。）

现在更难的部分是将端点名称与旧代码库中的MME设备相关联。

Answer 2

我发现了使用注册表查找音频设备的全名（输入和输出）的另一种方法。

在Windows 7和Windows 10上工作。

 1. drop USER 'user_name'@'localhost';
    flush privileges;
    CREATE USER 'user_name'@'localhost' IDENTIFIED BY 'user_name';
    GRANT ALL PRIVILEGES ON * . * TO 'user_name'@'localhost';
    ALTER USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 
    'user_name';

 2. drop USER 'user_name'@'localhost';
    flush privileges;
    CREATE USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 'user_name';
GRANT ALL PRIVILEGES ON * . * TO 'user_name'@'localhost'

 3. If the user is already created, the use the following command:

    ALTER USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 
        'user_name';

waveOutGetDevCaps，Win7和长设备名称

2 个答案: