Return Value:

• 0: Connected
• 1: Disconnected
• -1: Not available

 

Source Code:

int QueryNetworkAdapterStatus(string guidName)

{

    string str = "\\\\.\\";

    str += guidName;

    HANDLE m_hNetworkCardHandle = ::CreateFileA(

        str.c_str(),

        0,

        FILE_SHARE_READ,

        NULL,

        OPEN_EXISTING,

        0,

        INVALID_HANDLE_VALUE

    );

    if (m_hNetworkCardHandle == INVALID_HANDLE_VALUE)

        return -1;

    ULONG ConnectedState = 0;

    ULONG BytesWritten = 0;

    ULONG OidCode = OID_GEN_MEDIA_CONNECT_STATUS;

    if (0 != ::DeviceIoControl(m_hNetworkCardHandle,

        IOCTL_NDIS_QUERY_GLOBAL_STATS,

        &OidCode,

        sizeof(OidCode),

        &ConnectedState,

        sizeof(ConnectedState),

        &BytesWritten,

        NULL))

    {

        ::CloseHandle(m_hNetworkCardHandle);

        return ConnectedState;

    }

    else {

        ::CloseHandle(m_hNetworkCardHandle);

        return -1;

    }

}