这里列出了所有类成员，并附带类的详细说明:

- u -

• uart_tx_func : core_at_handle_t
• uint16 : mqtt_property_t
• uint32 : mqtt_property_t
• uint8 : mqtt_property_t
• unsub_ack : aiot_mqtt_recv_t
• update : aiot_devinfo_msg_t , aiot_shadow_msg_t
• update_reply : aiot_compress_recv_t , aiot_task_recv_t
• upload_id : aiot_mqtt_upload_desc_t
• uploadid : aiot_mqtt_upload_result_t
• urc_register : at_device_t
• urc_register_size : at_device_t
• url : aiot_download_task_desc_t
• user_data : core_at_handle_t
• userdata : aiot_mqtt_topic_map_t , aiot_mqtt_upload_file_opt_t , tunnel_switch_handler_t
• username : aiot_dynregmq_recv_t