ROS2入门之服务

创建用于通信的公共协议包

创建protocol包

cd src/
ros2 pkg create protocol --build-type ament_cmake --dependencies rosidl_default_generators

创建msg和srv目录用于保存自定义的消息和服务定义

命名时注意要符合该正则表达式

创建HelloWorld.msg

string data

创建AddTwoInts.srv

int64 a
int64 b
---
int64 sum

CMakeLists.txt

cmake_minimum_required(VERSION 3.8)
project(protocol)

# Default to C++14
if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 14)
endif()

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()

# find dependencies
find_package(ament_cmake REQUIRED)
find_package(rosidl_default_generators REQUIRED)

rosidl_generate_interfaces(${PROJECT_NAME}
  "msg/HelloWorld.msg"
  "srv/AddTwoInts.srv"
)

if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  # the following line skips the linter which checks for copyrights
  # comment the line when a copyright and license is added to all source files
  set(ament_cmake_copyright_FOUND TRUE)
  # the following line skips cpplint (only works in a git repo)
  # comment the line when this package is in a git repo and when
  # a copyright and license is added to all source files
  set(ament_cmake_cpplint_FOUND TRUE)
  ament_lint_auto_find_test_dependencies()
endif()

ament_export_dependencies(rosidl_default_runtime)
ament_package()

package.xml

<?xml version="1.0"?>
<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
<package format="3">
  <name>protocol</name>
  <version>0.0.0</version>
  <description>TODO: Package description</description>
  <maintainer email="wenqi.sun@narwal.com">root</maintainer>
  <license>TODO: License declaration</license>

  <buildtool_depend>ament_cmake</buildtool_depend>

  <depend>rosidl_default_generators</depend>

  <test_depend>ament_lint_auto</test_depend>
  <test_depend>ament_lint_common</test_depend>

  <member_of_group>rosidl_interface_packages</member_of_group>

  <export>
    <build_type>ament_cmake</build_type>
  </export>
</package>

执行编译

cd ..
colcon build