task.py 文件源码

def devices(self):
        """
        List[:class:`nidaqmx.system.device.Device`]: Indicates a list 
            of Device objects representing all the devices in the task.
        """
        cfunc = lib_importer.windll.DAQmxGetTaskDevices
        if cfunc.argtypes is None:
            with cfunc.arglock:
                if cfunc.argtypes is None:
                    cfunc.argtypes = [
                        lib_importer.task_handle, ctypes.c_char_p,
                        ctypes.c_uint]

        temp_size = 0
        while True:
            val = ctypes.create_string_buffer(temp_size)

            size_or_code = cfunc(
                self._handle, val, temp_size)

            if is_string_buffer_too_small(size_or_code):
                # Buffer size must have changed between calls; check again.
                temp_size = 0
            elif size_or_code > 0 and temp_size == 0:
                # Buffer size obtained, use to retrieve data.
                temp_size = size_or_code
            else:
                break

        check_for_error(size_or_code)

        return [Device(v) for v in
                unflatten_channel_string(val.value.decode('ascii'))]