'常量;
       Private Const WM_USER = &H400
        Private Const WS_CHILD = &H40000000
        Private Const WS_VISIBLE = &H10000000
        Private Const SWP_NOMOVE = &H2
        Private Const SWP_NOZORDER = &H4

        Private Const WM_CAP_START = &H400
        Private Const WM_CAP_STOP = WM_CAP_START + 68
        Private Const WM_CAP_DRIVER_CONNECT = WM_USER + 10
        Private Const WM_CAP_DRIVER_DISCONNECT = WM_USER + 11


' 关闭指令;
SendMessage(m_deviceid, WM_CAP_DRIVER_DISCONNECT, 0, 0)