#include<cstdlib>
#include"ros/ros.h"
#include"my_package/AddTwoInts.h"
int main(int argc, char **argv)
{
ros::init(argc, argv, "add_two_ints_client");
if (argc !=3)
{
ROS_INFO("usage:add_two_ints_client X Y");
return 1;
}
ros::NodeHandle n;
ros::ServiceClient client = n.serviceClient<my_package::AddTwoInts>("add_two_ints");
my_package::AddTwoInts srv;
srv.request.a=atoll(argv[1]);
srv.request.b=atoll(argv[2]);
if (client.call(srv))
{
ROS_INFO("Sum: %ld",(long int)srv.response.sum);
}
else
{
ROS_ERROR("Failed to call service add_two_ints");
return 1;
}
return 0;
}
1,创建Client
ros::ServiceClient client = n.serviceClient<my_package::AddTwoInts>("add_two_ints");
创建一个名为add_two_ints的服务,指定服务类型为:my_package::AddTwoInts
2,发布服务请求
my_package::AddTwoInts srv;
srv.request.a=atoll(argv[1]);
srv.request.b=atoll(argv[2]);
实例化一个服务数据类型的变量,该变量包括两个成员:request和response。
if (client.call(srv))
{
ROS_INFO("Sum: %ld",(long int)srv.response.sum);
}
else
{
ROS_ERROR("Failed to call service add_two_ints");
return 1;
}
进行服务调用,调用成功返回true,访问srv.response即可获取服务请求的结果。如果调用失败返回false,srv.response不可用。服务中的Client类似于话题中的Publisher,实现流程如下:
1,初始化ROS节点
2,创建一个Client实例
3,发布服务请求数据
4,等待Server处理后的应答结果
编译功能包:
编辑CMakelist.txt加入一下内容:
add_executable(service
src/service.cpp
)
target_link_libraries(service
${catkin_LIBRARIES}
)
add_dependencies(service ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
add_executable(client
src/client.cpp
)
target_link_libraries(client
${catkin_LIBRARIES}
)
add_dependencies(client ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})