古月居 ROS 21 讲6

古月居 ROS 21 讲

6、客户端Client的编程实现

创建learning service 在是src里写代码

程序流程

/**
 * 该例程将请求/spawn服务，服务数据类型turtlesim::Spawn
 */
//包含ros头文件以及turtlesim/Spawn这种数据类型的头文件
#include <ros/ros.h>
#include <turtlesim/Spawn.h>

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

    // 创建节点句柄
        ros::NodeHandle node;

    // 发现/spawn服务后，创建一个服务客户端，连接名为/spawn的service
        ros::service::waitForService("/spawn");
        //循环等待spawn服务
        ros::ServiceClient add_turtle = node.serviceClient<turtlesim::Spawn>("/spawn");
		//给spawn服务发送请求
		
    // 初始化turtlesim::Spawn的请求数据（requst）
        turtlesim::Spawn srv;
        srv.request.x = 2.0;
        srv.request.y = 2.0;
        srv.request.name = "turtle2";
   // 请求服务调用
        ROS_INFO("Call service to spwan turtle[x:%0.6f, y:%0.6f, name:%s]",
                         srv.request.x, srv.request.y, srv.request.name.c_str());

        add_turtle.call(srv);
    //请求客户端发送的方法是call，将requst发出去
        // 显示服务调用结果
        ROS_INFO("Spwan turtle successfully [name:%s]", srv.response.name.c_str());

        return 0;
};