指定用戶端資訊

某些設備磁碟機會使用第二個引數中提供的用戶端資訊來優化裝置效能。 您的應用程式至少應該提供包含其名稱、主要版本號碼、次要版本號碼和修訂編號的字串。 這些是範例應用程式所提供的欄位。

#define CLIENT_NAME         L"WPD Sample Application"
#define CLIENT_MAJOR_VER    1
#define CLIENT_MINOR_VER    0
#define CLIENT_REVISION     2

範例應用程式中的 函 GetClientInformation 式會以用戶端資訊建立並填入 IPortableDeviceValues 介面。 此函式有兩個主要部分。 第一個部分會藉由呼叫 CoCreateInstance 函式來建立可攜式裝置值物件的實例。

HRESULT hr = CoCreateInstance(CLSID_PortableDeviceValues,
                              NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_PPV_ARGS(ppClientInformation));

第二個部分會設定可攜式裝置值物件中的用戶端資訊。

if (SUCCEEDED(hr))
{
    // Attempt to set all bits of client information
    hr = (*ppClientInformation)->SetStringValue(WPD_CLIENT_NAME, CLIENT_NAME);
    if (FAILED(hr))
    {
        printf("! Failed to set WPD_CLIENT_NAME, hr = 0x%lx\n",hr);
    }

    hr = (*ppClientInformation)->SetUnsignedIntegerValue(WPD_CLIENT_MAJOR_VERSION, CLIENT_MAJOR_VER);
    if (FAILED(hr))
    {
        printf("! Failed to set WPD_CLIENT_MAJOR_VERSION, hr = 0x%lx\n",hr);
    }

    hr = (*ppClientInformation)->SetUnsignedIntegerValue(WPD_CLIENT_MINOR_VERSION, CLIENT_MINOR_VER);
    if (FAILED(hr))
    {
        printf("! Failed to set WPD_CLIENT_MINOR_VERSION, hr = 0x%lx\n",hr);
    }

    hr = (*ppClientInformation)->SetUnsignedIntegerValue(WPD_CLIENT_REVISION, CLIENT_REVISION);
    if (FAILED(hr))
    {
        printf("! Failed to set WPD_CLIENT_REVISION, hr = 0x%lx\n",hr);
    }

    //  Some device drivers need to impersonate the caller in order to function correctly.  Since our application does not
    //  need to restrict its identity, specify SECURITY_IMPERSONATION so that we work with all devices.
    hr = (*ppClientInformation)->SetUnsignedIntegerValue(WPD_CLIENT_SECURITY_QUALITY_OF_SERVICE, SECURITY_IMPERSONATION);
    if (FAILED(hr))
    {
        printf("! Failed to set WPD_CLIENT_SECURITY_QUALITY_OF_SERVICE, hr = 0x%lx\n",hr);
    }
}
else
{
    printf("! Failed to CoCreateInstance CLSID_PortableDeviceValues, hr = 0x%lx\n",hr);
}

相關主題

IPortableDevice 介面

IPortableDeviceValues 介面

程式設計指南