ros2 publiser 最容易理解的代码（C++版)

// Copyright 2016 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include 
#include 

#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/string.hpp"

using namespace std::chrono_literals;

/* We do not recommend this style anymore, because composition of multiple
 * nodes in the same executable is not possible. Please see one of the subclass
 * examples for the "new" recommended styles. This example is only included
 * for completeness because it is similar to "classic" standalone ROS nodes. */

int main(int argc, char * argv[])
{
  rclcpp::init(argc, argv);
  auto node = rclcpp::Node::make_shared("minimal_publisher");
  auto publisher = node->create_publisher("topic", 10);
  std_msgs::msg::String message;
  auto publish_count = 0;
  rclcpp::WallRate loop_rate(500ms);

  while (rclcpp::ok()) {
    message.data = "Hello, world! " + std::to_string(publish_count++);
    RCLCPP_INFO(node->get_logger(), "Publishing: '%s'", message.data.c_str());
    try {
      publisher->publish(message);
      rclcpp::spin_some(node);
    } catch (const rclcpp::exceptions::RCLError & e) {
      RCLCPP_ERROR(
        node->get_logger(),
        "unexpectedly failed with %s",
        e.what());
    }
    loop_rate.sleep();
  }
  rclcpp::shutdown();
  return 0;
}

ros2官方使用的那个代码实在是需要花费很多时间才能去理解掉那个代码，但是这个代码相对而言应该好理解的多，我推荐使用这个代码