ros2中Qos的C++配置方法

1. dds_debug.hpp

#ifndef DDS_DEBUG__DDS_DEBUG_HPP_
#define DDS_DEBUG__DDS_DEBUG_HPP_

#include <rclcpp/rclcpp.hpp>
#include <rclcpp/qos.hpp>
#include <rmw/types.h>
#include <sensor_msgs/msg/imu.hpp>

const rmw_qos_profile_t my_custom_qos_profile = 
{
    RMW_QOS_POLICY_HISTORY_KEEP_LAST,
    10,
    RMW_QOS_POLICY_RELIABILITY_RELIABLE,
    RMW_QOS_POLICY_DURABILITY_VOLATILE,
    RMW_DURATION_INFINITE,
    RMW_DURATION_INFINITE,
    RMW_QOS_POLICY_LIVELINESS_AUTOMATIC,
    RMW_DURATION_INFINITE,
    false
};

class DDS_debug : public rclcpp::Node
{
public:
    explicit DDS_debug();
    ~DDS_debug();

protected:
    void on_timer();

private:
    unsigned int cnt;
    rclcpp::Publisher<sensor_msgs::msg::Imu>::SharedPtr imu_pub_;
    rclcpp::TimerBase::SharedPtr timer_;
};

#endif

 2. dds_debug.cpp

#include "dds_debug/dds_debug.hpp"

DDS_debug::DDS_debug() 
    : Node("dds_debug")
    , cnt(0)
{
    auto qos = rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(my_custom_qos_profile), my_custom_qos_profile);

    imu_pub_ = create_publisher<sensor_msgs::msg::Imu>("/sensing/imu/tamagawa/imu_raw", qos);
    
    constexpr double period_s = 0.1;
    constexpr std::chrono::nanoseconds period_ns = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::duration<double>(period_s));
    timer_ = rclcpp::create_timer(this, get_clock(), period_ns, std::bind(&DDS_debug::on_timer, this));
}

DDS_debug::~DDS_debug() {}

void DDS_debug::on_timer() {
    cnt++;
    if (cnt <= 50) {
        sensor_msgs::msg::Imu imu_msg;
        imu_pub_->publish(imu_msg);
    }
}

 3. dds_debug_node.cpp

#include "dds_debug/dds_debug.hpp"

int main(int argc, char** argv) {  
  rclcpp::init(argc, argv);
  rclcpp::spin(std::make_shared<DDS_debug>());
  rclcpp::shutdown();

  return 0;
}