@小鱼 这点感觉不如ROS1的spinOnce好用，一般处理数据都是需要订阅数据的同时，定时对数据进行处理和结果发布的。
那你说的回调组是看官方教程的Demos这一章中Setting up efficient intra-process commnunication这一节吗？
还是Intermediate一章中的Composing multiple nodes in a single process这一小节？

ros2 bag play -s sqlites3 XXX.db3。
指定读取方式

@1206768372 网上搜了下,这个错误好像是vscode中环境配置造成的,你试试直接在电脑的终端里运行程序看看.

@望天 这个不借，可以试试

@凌云 可以看一下动手学ROS2的文档和代码,我都是用类来实现的

@小鱼 ok鱼哥 解决了 学到了 。然后也会注意一下提问方式。

@小鱼 没有数据哎，只有话题信息

@小鱼 base版有什么限制吗？和普通的相比？

@朝雨浥轻尘 这个不难,你需要写个代码来订阅数据,数据是个数组,你把每个数据遍历一遍,计算每个中心点的欧式距离,选择最小的那个的id记录下来.具体编程操作像这样子:

https://www.runoob.com/cprogramming/c-examples-smallest-array-element.html

#include <stdio.h> int main() { int array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0}; int loop, smallest; smallest = array[0]; for(loop = 1; loop < 10; loop++) { if( smallest > array[loop] ) smallest = array[loop]; } printf("最小元素为 %d", smallest); return 0; }

@1279063580 记得保存文件哈

@Gene ubuntu18估计你要自己手动下载libabsl的源码进行安装了

可以了可以了 感谢

@小鱼 静候佳音

@望天 尽量一次性把话说完哈,社区交流不要当作群聊一样,详细和具体才有意义.

不是humble分支,humble版本的教程代码仓库地址: https://github.com/fishros/d2lros2-humble-code

@龙腾龙卷风 rti，需要手动装一下哈，我搞错了，用apt应该就能装。

@hudie ros2你可以使用声明周期节点，这样可以通过相关的服务进行控制节点的启动关闭等声明周期。

具体使用请参考：https://github.com/ros2/demos/blob/humble/lifecycle/README.rst

@小鱼 msg格式如下：

[sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0), sensor_abstraction_msgs.msg.VideoObject(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=0, nanosec=0), frame_id=''), obj_id=0, obj_cam_id=0, obj_fusion_sensor=0, obj_status=0, obj_motion_status=0, obj_type=0, obj_type_conf=0.0, obj_exsit_prob=0.0, obj_length=0.0, obj_width=0.0, obj_height=0.0, obj_heading_angle=-3.140000104904175, obj_heading_angle_std=0.0, obj_yawrate=-2.2339999675750732, obj_lng_absolute_velocity=-30.0, obj_lat_absolute_velocity=-50.0, obj_lng_absolute_velocity_std=0.0, obj_lat_absolute_velocity_std=0.0, obj_lng_relative_velocity=-120.0, obj_lat_relative_velocity=-50.0, obj_lng_relative_velocity_std=0.0, obj_lat_relative_velocity_std=0.0, obj_lng_absolute_acceleration=-10.300000190734863, obj_lat_absolute_acceleration=-10.300000190734863, obj_lng_absolute_acceleration_std=0.0, obj_lat_absolute_acceleration_std=0.0, obj_lng_relative_acceleration=-10.300000190734863, obj_lat_relative_acceleration=0.0, obj_lng_relative_acceleration_std=0.0, obj_lat_relative_acceleration_std=0.0, obj_nearest_side=0, obj_in_lane_position=0, obj_turn_light_status=0, obj_brake_light_status=0, obj_ttc=-8.0, obj_ttc_std=0.0, obj_boundary_x1=0, obj_boundary_y1=0, obj_boundary_x2=0, obj_boundary_y2=0, obj_boundary_x3=0, obj_boundary_y3=0, obj_boundary_x4=0, obj_boundary_y4=0, obj_3_d_boundary_bottom_x=0, obj_3_d_boundary_bottom_y=0, obj_3_d_boundary_top_x=0, obj_3_d_boundary_top_y=0, obj_3_d_boundary_left_x=0, obj_3_d_boundary_left_y=0, obj_3_d_boundary_right_x=0, obj_3_d_boundary_right_y=0, obj_lateral=-100.0, obj_lateral_std=0.0, obj_longitudinal=-200.0, obj_longitudinal_std=0.0, obj_vertical=0.0, obj_vertical_std=0.0, obj_center_angle=-1.5709999799728394, obj_center_angle_std=0.0, obj_total_age=0, obj_init_age=0, obj_measure_age=0, obj_predict_age=0, obj_boundary_min_angle=0.0, obj_boundary_max_angle=0.0),...]

@小鱼
我多播弄成功了，两个主机都运行这个命令
route add -net 224.0.0.0 netmask 224.0.0.0 eth0

@刚刚小飞机 在 [foxy][ros2bag-convert]转换msg失败 中说：

message_fields = message.get_fields_and_field_types()

AttributeError: 'list' object has no attribute 'get_fields_and_field_types'

把这个消息打印出来看看具体内容先,估计是我内部处理有一些小bug