订阅者

Author: HuangCongQing

catkin_wp/src/learning_topic/script/velocity_publisher.py

@@ -28,8 +28,7 @@ def velocity_publisher():
 
 		# 发布消息
         turtle_vel_pub.publish(vel_msg)
-    	rospy.loginfo("Publsh turtle velocity command[%0.2f m/s, %0.2f rad/s]", 
-				vel_msg.linear.x, vel_msg.angular.z)
+        rospy.loginfo("Publsh turtle velocity command[%0.2f m/s, %0.2f rad/s]", vel_msg.linear.x, vel_msg.angular.z)
 
 		# 按照循环频率延时
         rate.sleep()

catkin_wp/src/learning_topic/src/pose_subscriber.cpp

@@ -0,0 +1,34 @@
+/***********************************************************************
+Copyright 2020 GuYueHome (www.guyuehome.com).
+***********************************************************************/
+
+/**
+ * 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;
+}