setupdi.py 文件源码

def open(self):
        """
        Open device to query properties

        :return: context
        """
        handle = _setupapi.SetupDiCreateDeviceInfoList(None, None)
        if handle == -1:
            err_no = ctypes.GetLastError()
            raise WindowsError(err_no, ctypes.FormatError(err_no))
        try:
            dev_info = DeviceInfoData()
            if not _setupapi.SetupDiOpenDeviceInfoW(handle, ctypes.create_unicode_buffer(self._instance_id), None,
                                                    DIOD_INHERIT_CLASSDRVS, ctypes.byref(dev_info)):
                err_no = ctypes.GetLastError()
                raise WindowsError(err_no, ctypes.FormatError(err_no))
            self._handle = (handle, dev_info, self._handle)  # Stack
            yield self
        finally:
            if self._handle is not None and \
                            self._handle[0] == handle:  # If last handle is opened in this function, pop it
                self._handle = self._handle[2]
            _setupapi.SetupDiDestroyDeviceInfoList(handle)  # Close handle