#终端显示错误类型为:
/home/why/catkin_ws/src/learning_service/src/turtle_command_server.cpp:29:5: error: expected ‘;’ before ‘return’
return true;
^
learning_service/CMakeFiles/turtle_command_server.dir/build.make:62: recipe for target ‘learning_service/CMakeFiles/turtle_command_server.dir/src/turtle_command_server.cpp.o’ failed
make[2]: *** [learning_service/CMakeFiles/turtle_command_server.dir/src/turtle_command_server.cpp.o] Error 1
CMakeFiles/Makefile2:444: recipe for target ‘learning_service/CMakeFiles/turtle_command_server.dir/all’ failed
make[1]: *** [learning_service/CMakeFiles/turtle_command_server.dir/all] Error 2
Makefile:138: recipe for target ‘all’ failed
make: *** [all] Error 2
Invoking “make -j4 -l4” failed
错误出现在:工程ros_21_tutorials下功能包learning_service的src目录下turtle_command_server.cpp文件
更正后的代码如下
/***********************************************************************
Copyright 2020 GuYueHome (www.guyuehome.com).
***********************************************************************/
/**
* 该例程将执行/turtle_command服务,服务数据类型std_srvs/Trigger
*/
#include <ros/ros.h>
#include <geometry_msgs/Twist.h>
#include <std_srvs/Trigger.h>
ros::Publisher turtle_vel_pub;
bool pubCommand = false;
// service回调函数,输入参数req,输出参数res
bool commandCallback(std_srvs::Trigger::Request &req,
std_srvs::Trigger::Response &res)
{
pubCommand = !pubCommand;
// 显示请求数据
ROS_INFO("Publish turtle velocity command [%s]", pubCommand==true?"Yes":"No");
// 设置反馈数据
res.success = true;
res.message = "Change turtle command state!";
return true;
}
int main(int argc, char **argv)
{
// ROS节点初始化
ros::init(argc, argv, "turtle_command_server");
// 创建节点句柄
ros::NodeHandle n;
// 创建一个名为/turtle_command的server,注册回调函数commandCallback
ros::ServiceServer command_service = n.advertiseService("/turtle_command", commandCallback);
// 创建一个Publisher,发布名为/turtle1/cmd_vel的topic,消息类型为geometry_msgs::Twist,队列长度10
turtle_vel_pub = n.advertise<geometry_msgs::Twist>("/turtle1/cmd_vel", 10);
// 循环等待回调函数
ROS_INFO("Ready to receive turtle command.");
// 设置循环的频率
ros::Rate loop_rate(10);
while(ros::ok())
{
// 查看一次回调函数队列
ros::spinOnce();
// 如果标志为true,则发布速度指令
if(pubCommand)
{
geometry_msgs::Twist vel_msg;
vel_msg.linear.x = 0.5;
vel_msg.angular.z = 0.2;
turtle_vel_pub.publish(vel_msg);
}
//按照循环频率延时
loop_rate.sleep();
}
return 0;
}```