ros创建一个服务和客户端，完成随意输入3个整数，求取三个整数中的最大值。c++

以下是一个简单的ROS服务和客户端代码，用于求取三个整数中的最大值。

服务端代码：

#include "ros/ros.h"
#include "demo_pkg/MaxInt.h"

bool max_int(demo_pkg::MaxInt::Request &req, demo_pkg::MaxInt::Response &res)
{
  res.max = req.a;
  if (req.b > res.max) {
    res.max = req.b;
  }
  if (req.c > res.max) {
    res.max = req.c;
  }
  ROS_INFO("Max of %d, %d and %d is %d", req.a, req.b, req.c, res.max);
  return true;
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "max_int_server");
  ros::NodeHandle n;

  ros::ServiceServer service = n.advertiseService("max_int", max_int);
  ROS_INFO("Ready to find the max of 3 integers.");
  ros::spin();

  return 0;
}

客户端代码：

#include "ros/ros.h"
#include "demo_pkg/MaxInt.h"
#include <cstdlib>

int main(int argc, char **argv)
{
  ros::init(argc, argv, "max_int_client");
  if (argc != 4) {
    ROS_INFO("Usage: max_int_client a b c");
    return 1;
  }

  ros::NodeHandle n;
  ros::ServiceClient client = n.serviceClient<demo_pkg::MaxInt>("max_int");
  demo_pkg::MaxInt srv;
  srv.request.a = atoi(argv[1]);
  srv.request.b = atoi(argv[2]);
  srv.request.c = atoi(argv[3]);
  if (client.call(srv)) {
    ROS_INFO("Max of %d, %d and %d is %d", srv.request.a, srv.request.b, srv.request.c, srv.response.max);
  } else {
    ROS_ERROR("Failed to call service max_int");
    return 1;
  }

  return 0;
}

在运行之前，请确保已经创建了一个名为"demo_pkg"的ROS软件包，其中包含一个名为"MaxInt.srv"的服务文件，用于定义服务的请求和响应类型。"MaxInt.srv"文件内容如下：

int64 a
int64 b
int64 c
---
int64 max

在终端中先运行服务端：

$ rosrun demo_pkg max_int_server

然后在另一个终端中运行客户端，输入3个整数，例如：

$ rosrun demo_pkg max_int_client 5 2 7

将输出：

Max of 5, 2 and 7 is 7