【ROS2指南-18】编写Action服务器和客户端

1.1 创建 action_tutorials_cpp 包

进入您在上一教程中创建的操作工作区（记得为工作区提供源），并为 C++ 操作服务器创建一个新包：

#ifndef ACTION_TUTORIALS_CPP__VISIBILITY_CONTROL_H_
#define ACTION_TUTORIALS_CPP__VISIBILITY_CONTROL_H_#ifdef __cplusplus
extern "C"
{
#endif// This logic was borrowed (then namespaced) from the examples on the gcc wiki:
//     https://gcc.gnu.org/wiki/Visibility#if defined _WIN32 || defined __CYGWIN__#ifdef __GNUC__#define ACTION_TUTORIALS_CPP_EXPORT __attribute__ ((dllexport))#define ACTION_TUTORIALS_CPP_IMPORT __attribute__ ((dllimport))#else#define ACTION_TUTORIALS_CPP_EXPORT __declspec(dllexport)#define ACTION_TUTORIALS_CPP_IMPORT __declspec(dllimport)#endif#ifdef ACTION_TUTORIALS_CPP_BUILDING_DLL#define ACTION_TUTORIALS_CPP_PUBLIC ACTION_TUTORIALS_CPP_EXPORT#else#define ACTION_TUTORIALS_CPP_PUBLIC ACTION_TUTORIALS_CPP_IMPORT#endif#define ACTION_TUTORIALS_CPP_PUBLIC_TYPE ACTION_TUTORIALS_CPP_PUBLIC#define ACTION_TUTORIALS_CPP_LOCAL
#else#define ACTION_TUTORIALS_CPP_EXPORT __attribute__ ((visibility("default")))#define ACTION_TUTORIALS_CPP_IMPORT#if __GNUC__ >= 4#define ACTION_TUTORIALS_CPP_PUBLIC __attribute__ ((visibility("default")))#define ACTION_TUTORIALS_CPP_LOCAL  __attribute__ ((visibility("hidden")))#else#define ACTION_TUTORIALS_CPP_PUBLIC#define ACTION_TUTORIALS_CPP_LOCAL#endif#define ACTION_TUTORIALS_CPP_PUBLIC_TYPE
#endif#ifdef __cplusplus
}
#endif#endif  // ACTION_TUTORIALS_CPP__VISIBILITY_CONTROL_H_

add_library(action_server SHAREDsrc/fibonacci_action_server.cpp)
target_include_directories(action_server PRIVATE$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>$<INSTALL_INTERFACE:include>)
target_compile_definitions(action_serverPRIVATE "ACTION_TUTORIALS_CPP_BUILDING_DLL")
ament_target_dependencies(action_server"action_tutorials_interfaces""rclcpp""rclcpp_action""rclcpp_components")
rclcpp_components_register_node(action_server PLUGIN "action_tutorials_cpp::FibonacciActionServer" EXECUTABLE fibonacci_action_server)
install(TARGETSaction_serverARCHIVE DESTINATION libLIBRARY DESTINATION libRUNTIME DESTINATION bin)

ros2 run action_tutorials_cpp fibonacci_action_server

#include <functional>
#include <future>
#include <memory>
#include <string>
#include <sstream>#include "action_tutorials_interfaces/action/fibonacci.hpp"#include "rclcpp/rclcpp.hpp"
#include "rclcpp_action/rclcpp_action.hpp"
#include "rclcpp_components/register_node_macro.hpp"namespace action_tutorials_cpp
{
class FibonacciActionClient : public rclcpp::Node
{
public:using Fibonacci = action_tutorials_interfaces::action::Fibonacci;using GoalHandleFibonacci = rclcpp_action::ClientGoalHandle<Fibonacci>;explicit FibonacciActionClient(const rclcpp::NodeOptions & options): Node("fibonacci_action_client", options){this->client_ptr_ = rclcpp_action::create_client<Fibonacci>(this->get_node_base_interface(),this->get_node_graph_interface(),this->get_node_logging_interface(),this->get_node_waitables_interface(),"fibonacci");this->timer_ = this->create_wall_timer(std::chrono::milliseconds(500),std::bind(&FibonacciActionClient::send_goal, this));}void send_goal(){using namespace std::placeholders;this->timer_->cancel();if (!this->client_ptr_->wait_for_action_server()) {RCLCPP_ERROR(this->get_logger(), "Action server not available after waiting");rclcpp::shutdown();}auto goal_msg = Fibonacci::Goal();goal_msg.order = 10;RCLCPP_INFO(this->get_logger(), "Sending goal");auto send_goal_options = rclcpp_action::Client<Fibonacci>::SendGoalOptions();send_goal_options.goal_response_callback =std::bind(&FibonacciActionClient::goal_response_callback, this, _1);send_goal_options.feedback_callback =std::bind(&FibonacciActionClient::feedback_callback, this, _1, _2);send_goal_options.result_callback =std::bind(&FibonacciActionClient::result_callback, this, _1);this->client_ptr_->async_send_goal(goal_msg, send_goal_options);}private:rclcpp_action::Client<Fibonacci>::SharedPtr client_ptr_;rclcpp::TimerBase::SharedPtr timer_;void goal_response_callback(std::shared_future<GoalHandleFibonacci::SharedPtr> future){auto goal_handle = future.get();if (!goal_handle) {RCLCPP_ERROR(this->get_logger(), "Goal was rejected by server");} else {RCLCPP_INFO(this->get_logger(), "Goal accepted by server, waiting for result");}}void feedback_callback(GoalHandleFibonacci::SharedPtr,const std::shared_ptr<const Fibonacci::Feedback> feedback){std::stringstream ss;ss << "Next number in sequence received: ";for (auto number : feedback->partial_sequence) {ss << number << " ";}RCLCPP_INFO(this->get_logger(), ss.str().c_str());}void result_callback(const GoalHandleFibonacci::WrappedResult & result){switch (result.code) {case rclcpp_action::ResultCode::SUCCEEDED:break;case rclcpp_action::ResultCode::ABORTED:RCLCPP_ERROR(this->get_logger(), "Goal was aborted");return;case rclcpp_action::ResultCode::CANCELED:RCLCPP_ERROR(this->get_logger(), "Goal was canceled");return;default:RCLCPP_ERROR(this->get_logger(), "Unknown result code");return;}std::stringstream ss;ss << "Result received: ";for (auto number : result.result->sequence) {ss << number << " ";}RCLCPP_INFO(this->get_logger(), ss.str().c_str());rclcpp::shutdown();}
};  // class FibonacciActionClient}  // namespace action_tutorials_cppRCLCPP_COMPONENTS_REGISTER_NODE(action_tutorials_cpp::FibonacciActionClient)

add_library(action_client SHAREDsrc/fibonacci_action_client.cpp)
target_include_directories(action_client PRIVATE$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>$<INSTALL_INTERFACE:include>)
target_compile_definitions(action_clientPRIVATE "ACTION_TUTORIALS_CPP_BUILDING_DLL")
ament_target_dependencies(action_client"action_tutorials_interfaces""rclcpp""rclcpp_action""rclcpp_components")
rclcpp_components_register_node(action_client PLUGIN "action_tutorials_cpp::FibonacciActionClient" EXECUTABLE fibonacci_action_client)
install(TARGETSaction_clientARCHIVE DESTINATION libLIBRARY DESTINATION libRUNTIME DESTINATION bin)

ros2 run action_tutorials_cpp fibonacci_action_client

您应该会看到已接受目标、正在打印的反馈以及最终结果的记录消息。