ros-订阅者subscriber的编程

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

在learning_topic/src文件内，创建pose_subscriber.cpp

 
#include 
#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;
}

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

cd ~/catkin_ws
catkin_make
source devel/setup.bash