C++入门 ros服务通信

一、开发环境

ubuntu20.04
ros版本noetic
参考视频
https://www.bilibili.com/video/BV1Ci4y1L7ZZ/?p=52&spm_id_from=333.1007.top_right_bar_window_history.content.click&vd_source=4cd1b6f268e2a29a11bea5d2568836ee

二、编写srv文件

在功能包下面创建srv文件夹（srv文件夹和src文件夹并列），在srv文件夹中创建AddInt.srv文件
AddInt.srv

int32 num1
int32 num2
---
int32 sum

三、编写服务端

smain.cpp

#include "ros/ros.h"
#include "/home/leon/project/ros/helloworld/ws/devel/include/addserver/AddInt.h"
#include <sstream>bool doNums(addserver::AddInt::Request &request,addserver::AddInt::Response &response)
{int num1 = request.num1;int num2 = request.num2;ROS_INFO("收到:%d,%d",num1,num2);int sum = num1 + num2;response.sum = sum;ROS_INFO("反馈:%d",sum);return true;
}//服务端
int main(int argc,char *argv[])
{//中文支持setlocale(LC_ALL,"");//初始化ros节点//指定节点名称ros::init(argc,argv,"server");//创建ros节点句柄ros::NodeHandle n;//创建服务对象ros::ServiceServer server = n.advertiseService("add",doNums);ros::spin();return 0;
}
//
//通过ros工具打印话题消息
//rostopic echo fang//通过命令方式调用服务
//rosservice call add "num1: 5 num2: 2"

四、编写客户端

cmain.cpp

#include "ros/ros.h"
#include "/home/leon/project/ros/helloworld/ws/devel/include/addserver/AddInt.h"
#include <sstream>bool doNums(addserver::AddInt::Request &request,addserver::AddInt::Response &response)
{int num1 = request.num1;int num2 = request.num2;ROS_INFO("收到:%d,%d",num1,num2);int sum = num1 + num2;response.sum = sum;ROS_INFO("反馈:%d",sum);return true;
}//服务调用端
int main(int argc,char *argv[])
{//中文支持setlocale(LC_ALL,"");if(argc != 3){ROS_INFO("参数个数不对");return 1;}//初始化ros节点//指定节点名称ros::init(argc,argv,"client");//创建ros节点句柄ros::NodeHandle n;//创建服务对象ros::ServiceClient client = n.serviceClient<addserver::AddInt>("add");addserver::AddInt to;to.request.num1 = atoi(argv[1]);to.request.num2 = atoi(argv[2]);//客户端先启动时等待服务器启动client.waitForExistence();//ros::service::waitForService("add");//功能同上一行bool flag = client.call(to);if(flag){ROS_INFO("响应结果:%d",to.response.sum);}else{ROS_INFO("响应失败");}return 0;
}
//
//通过ros工具打印话题消息
//rostopic echo fang//通过命令方式调用服务
//rosservice call add "num1: 5 num2: 2"

五、修改配置

package.xml

<?xml version="1.0"?>
<package format="2"><name>addserver</name><version>0.0.0</version><description>The addserver package</description><!-- One maintainer tag required, multiple allowed, one person per tag --><!-- Example:  --><!-- <maintainer email="jane.doe@example.com">Jane Doe</maintainer> --><maintainer email="leon@todo.todo">leon</maintainer><!-- One license tag required, multiple allowed, one license per tag --><!-- Commonly used license strings: --><!--   BSD, MIT, Boost Software License, GPLv2, GPLv3, LGPLv2.1, LGPLv3 --><license>TODO</license><!-- Url tags are optional, but multiple are allowed, one per tag --><!-- Optional attribute type can be: website, bugtracker, or repository --><!-- Example: --><!-- <url type="website">http://wiki.ros.org/addserver</url> --><!-- Author tags are optional, multiple are allowed, one per tag --><!-- Authors do not have to be maintainers, but could be --><!-- Example: --><!-- <author email="jane.doe@example.com">Jane Doe</author> --><!-- The *depend tags are used to specify dependencies --><!-- Dependencies can be catkin packages or system dependencies --><!-- Examples: --><!-- Use depend as a shortcut for packages that are both build and exec dependencies --><!--   <depend>roscpp</depend> --><!--   Note that this is equivalent to the following: --><!--   <build_depend>roscpp</build_depend> --><!--   <exec_depend>roscpp</exec_depend> --><!-- Use build_depend for packages you need at compile time: --><!--   <build_depend>message_generation</build_depend> --><!-- Use build_export_depend for packages you need in order to build against this package: --><!--   <build_export_depend>message_generation</build_export_depend> --><!-- Use buildtool_depend for build tool packages: --><!--   <buildtool_depend>catkin</buildtool_depend> --><!-- Use exec_depend for packages you need at runtime: --><!--   <exec_depend>message_runtime</exec_depend> --><!-- Use test_depend for packages you need only for testing: --><!--   <test_depend>gtest</test_depend> --><!-- Use doc_depend for packages you need only for building documentation: --><!--   <doc_depend>doxygen</doc_depend> --><buildtool_depend>catkin</buildtool_depend><build_depend>roscpp</build_depend><build_depend>std_msgs</build_depend><build_depend>message_generation</build_depend><build_export_depend>roscpp</build_export_depend><build_export_depend>std_msgs</build_export_depend><exec_depend>roscpp</exec_depend><exec_depend>std_msgs</exec_depend><exec_depend>message_runtime</exec_depend><!-- The export tag contains other, unspecified, tags --><export><!-- Other tools can request additional information be placed here --></export>
</package>

修改配置
CMakeLists.txt

cmake_minimum_required(VERSION 3.0.2)
project(addserver)## Compile as C++11, supported in ROS Kinetic and newer
# add_compile_options(-std=c++11)## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTSroscppstd_msgsmessage_generation
)## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()################################################
## Declare ROS messages, services and actions ##
################################################## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend tag for "message_generation"
##   * add a build_depend and a exec_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
##     but can be declared for certainty nonetheless:
##     * add a exec_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)## Generate messages in the 'msg' folder
# add_message_files(
#   FILES
#   Message1.msg
#   Message2.msg
# )## Generate services in the 'srv' folder
add_service_files(FILESAddInt.srv
)## Generate actions in the 'action' folder
# add_action_files(
#   FILES
#   Action1.action
#   Action2.action
# )## Generate added messages and services with any dependencies listed here
generate_messages(DEPENDENCIESstd_msgs
)################################################
## Declare ROS dynamic reconfigure parameters ##
################################################## To declare and build dynamic reconfigure parameters within this
## package, follow these steps:
## * In the file package.xml:
##   * add a build_depend and a exec_depend tag for "dynamic_reconfigure"
## * In this file (CMakeLists.txt):
##   * add "dynamic_reconfigure" to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * uncomment the "generate_dynamic_reconfigure_options" section below
##     and list every .cfg file to be processed## Generate dynamic reconfigure parameters in the 'cfg' folder
# generate_dynamic_reconfigure_options(
#   cfg/DynReconf1.cfg
#   cfg/DynReconf2.cfg
# )###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if your package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
#  INCLUDE_DIRS include
#  LIBRARIES addserverCATKIN_DEPENDS roscpp std_msgs message_runtime
#  DEPENDS system_lib
)###########
## Build ##
############# Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
# include${catkin_INCLUDE_DIRS}
)## Declare a C++ library
# add_library(${PROJECT_NAME}
#   src/${PROJECT_NAME}/addserver.cpp
# )## Add cmake target dependencies of the library
## as an example, code may need to be generated before libraries
## either from message generation or dynamic reconfigure
# add_dependencies(${PROJECT_NAME} ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})## Declare a C++ executable
## With catkin_make all packages are built within a single CMake context
## The recommended prefix ensures that target names across packages don't collide
add_executable(addserver src/smain.cpp)
add_executable(addclient src/cmain.cpp)## Rename C++ executable without prefix
## The above recommended prefix causes long target names, the following renames the
## target back to the shorter version for ease of user use
## e.g. "rosrun someones_pkg node" instead of "rosrun someones_pkg someones_pkg_node"
# set_target_properties(${PROJECT_NAME}_node PROPERTIES OUTPUT_NAME node PREFIX "")## Add cmake target dependencies of the executable
## same as for the library above
add_dependencies(addserver ${PROJECT_NAME}_gencpp)
add_dependencies(addclient ${PROJECT_NAME}_gencpp)## Specify libraries to link a library or executable target against
target_link_libraries(addserver${catkin_LIBRARIES}
)
target_link_libraries(addclient${catkin_LIBRARIES}
)#############
## Install ##
############## all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# catkin_install_python(PROGRAMS
#   scripts/my_python_script
#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )## Mark executables for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_executables.html
# install(TARGETS ${PROJECT_NAME}_node
#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )## Mark libraries for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_libraries.html
# install(TARGETS ${PROJECT_NAME}
#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   RUNTIME DESTINATION ${CATKIN_GLOBAL_BIN_DESTINATION}
# )## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
#   FILES_MATCHING PATTERN "*.h"
#   PATTERN ".svn" EXCLUDE
# )## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
#   # myfile1
#   # myfile2
#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )#############
## Testing ##
############### Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_addserver.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()## Add folders to be run by python nosetests
# catkin_add_nosetests(test)