如何实现一个订阅者
1.初始化ros节点 2.订阅需要的话题 3.循环等待话题信息,接收到消息后进入回调函数 4.在回调函数中完成消息处理
c++
在learning_topic/src文件内,创建pose_subscriber.cpp
/**
* 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;
}
配置cmakelist.txt
add_executable(pose_subscriber src/pose_subscriber.cpp)
target_link_libraries(pose_subscriber
${catkin_LIBRARIES}
)
编译
cd ~/catkin_ws
catkin_make
source devel/setup.bash
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