Catalog
五.订阅者编程实现

Topic Model
Topic Model


Create Subscriber Code(C++)

/**
* 该例程将订阅/turtle1/pose话题,消息类型turtlesim::Pose
*/
#include <ros/ros.h>
#include "turtlesim/Pose.h"

// 接收到订阅的消息后,会进入消息回调函数

void poseCallback(const turtlesim::Pose::ConstPtr& msg)
{
// 将接收到的消息打印出来
ROS_INFO("Turtle pose: x:%0.6f, y:%0.6f", msg->x, msg->y);
}

int main(int argc, char **argv)
{
// 初始化ROS节点
ros::init(argc, argv, "pose_subscriber");

// 创建节点句柄
ros::NodeHandle n;

// 创建一个Subscriber,订阅名为/turtle1/pose的topic,注册回调函数poseCallback
ros::Subscriber pose_sub = n.subscribe("/turtle1/pose", 10, poseCallback);

// 循环等待回调函数
ros::spin();

return 0;

}

Configure Code Compilation Rules

open CMakeLists.txt
add_executable(pose_subscriber src/pose_subscriber.cpp)
target_link_libraries(pose_subscriber ${catkin_LIBRARIES})


Build $ Run

cd ~/catkin_ws
catkin_make
source devel/setup.bash
roscore
rosrun turtlesim turtlesim_node
rosrun learning_topic pose_subscriber


Create Subscriber Code(Python)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 该例程将订阅/turtle1/pose话题,消息类型turtlesim::Pose

import rospy
from turtlesim.msg import Pose

def poseCallback(msg):
rospy.loginfo("Turtle pose: x:%0.6f, y:%0.6f", msg.x, msg.y)

def pose_subscriber():
# ROS节点初始化
rospy.init_node('pose_subscriber', anonymous=True)

# 创建一个Subscriber,订阅名为/turtle1/pose的topic,注册回调函数poseCallback
rospy.Subscriber("/turtle1/pose", Pose, poseCallback)

# 循环等待回调函数
rospy.spin()

if __name__ == '__main__':
pose_subscriber()
Author: Jone-Mark
Link: http://94.191.80.102:4000/2019/03/17/%E4%BA%94-%E8%AE%A2%E9%98%85%E8%80%85%E7%BC%96%E7%A8%8B%E5%AE%9E%E7%8E%B0/
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