1.查看service列表的代碼:
rosservice list
可以用代碼或者終端對列表中的服務進行調用:
rosservice call /服務名稱
2.service介紹
client負責發佈請求數據等待server處理 ---------------數據
server負責處理相應功能並返回應答數據--------------操作
3.自定義服務數據
在srv文件夾下的.srv文件,其中包括請求和應答的數據,用“- - -”進行分割。
(1)在Package.xml中添加功能包依賴
<build_depend>message_generation</build_depend>
<run_depend>message_runtime</run_depend>
(2)在CMakeLists.txt中添加功能包依賴
find_package(catkin REQUIRED COMPONENTS
roscpp
std_msgs
message_generation
)
add_service_files(
FILES
AddTwoInts.msg
)
4.編寫server和client代碼
server:
#include "ros/ros.h"
#include "learning_communication/AddTwoInts.h"
bool add(learning_communication::AddTwoInts::Request &req,
learning_communication::AddTwoInts::Response &res)
{
res.sum = req.a + req.b;
ROS_INFO("request: x=%ld, y=%ld", (long int)req.a, (long int)req.b);
ROS_INFO("sending back response: [%ld]", (long int)res.sum);
return true;
}
int main(int argc, char **argv)
{
ros::init(argc, argv, "add_two_ints_server");
ros::NodeHandle n;
ros::ServiceServer service = n.advertiseService("add_two_ints", add);
ROS_INFO("Ready to add two ints.");
ros::spin();
return 0;
client:
#include "ros/ros.h"
#include "learning_communication/AddTwoInts.h"
#include <cstdlib>
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<learning_communication::AddTwoInts>("add_two_ints");
beginner_tutorials::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;
}
5.編譯功能包
add_executable(add_two_ints_server src/add_two_ints_server.cpp)
target_link_libraries(add_two_ints_server ${catkin_LIBRARIES})
add_dependencies(add_two_ints_server beginner_tutorials_gencpp)
add_executable(add_two_ints_client src/add_two_ints_client.cpp)
target_link_libraries(add_two_ints_client ${catkin_LIBRARIES})
add_dependencies(add_two_ints_client beginner_tutorials_gencpp)
注意:add_executable中的第一個參數爲期望生成的可執行文件的而名稱,第二個參數爲源碼文件;target_link_libraries第一個參數與add_executable相同;