"raise Typeerror()" when sending a goal to "FollowWaypoints" server of Nav2 [closed]

edit

hi everyone, i am new for ros. i tried the example in the nav2(https://navigation.ros.org/getti... and want to use the 'FollowWaypoints' action server to navigate the robot by the given points. i wrote a pythonscript for the client. the robot should go to the given point, for example(0.2,1.3.0). but it does not work, i got a error 'rasing typeerror'. here is my python code for my "FollowWaypoints" client:

class ClientFollowPoints(Node):

    def __init__(self):
        super().__init__('client_follow_points')
        self._client = ActionClient(self, FollowWaypoints, '/FollowWaypoints')

    def send_points(self, points):
        msg = FollowWaypoints.Goal
        msg.poses = points

        self._client.wait_for_server()
        self._send_goal_future = self._client.send_goal_async(msg, feedback_callback=self.feedback_callback)
        self._send_goal_future.add_done_callback(self.goal_response_callback)

    def goal_response_callback(self, future):
        goal_handle = future.result()
        if not goal_handle.accepted:
            self.get_logger().info('Goal rejected')
            return

        self.get_logger().info('Goal accepted')

        self._get_result_future = goal_handle.get_result_async()
        self._get_result_future.add_done_callback(self.get_result_callback)

    def get_result_callback(self, future):
        result = future.result().result
        self.get_logger().info('Result: {0}'.format(result.missed_waypoints))

    def feedback_callback(self, feedback_msg):
        feedback = feedback_msg.feedback
        self.get_logger().info('Received feedback: {0}}'.format(feedback.current_waypoint))

and my main:

    rclpy.init(args=args)

    follow_points_client = ClientFollowPoints()
    print('client inited')

    rgoal = PoseStamped()
    rgoal.header.frame_id = "map"
    rgoal.header.stamp.sec = 0
    rgoal.header.stamp.nanosec = 0
    rgoal.pose.position.z = 0.0
    rgoal.pose.position.x = 0.2
    rgoal.pose.position.y = 1.3
    rgoal.pose.orientation.w = 1.0
    print(rgoal)
    mgoal = [rgoal]

    follow_points_client.send_points(mgoal)

    rclpy.spin(follow_points_client)

and my Trace back:

Traceback (most recent call last):
  File "/home/jing/htwg/tryForROS/dev_ws/install/follow_points_client/lib/follow_points_client/fp_client", line 11, in <module>
    load_entry_point('follow-points-client==0.0.0', 'console_scripts', 'fp_client')()
  File "/home/jing/htwg/tryForROS/dev_ws/install/follow_points_client/lib/python3.8/site-packages/follow_points_client/follow_points_client.py", line 58, in main
    follow_points_client.send_points([rgoal])
  File "/home/jing/htwg/tryForROS/dev_ws/install/follow_points_client/lib/python3.8/site-packages/follow_points_client/follow_points_client.py", line 20, in send_points
    self._send_goal_future = self._client.send_goal_async(msg, feedback_callback=self.feedback_callback)
  File "/opt/ros/foxy/lib/python3.8/site-packages/rclpy/action/client.py", line 421, in send_goal_async
    raise TypeError()
TypeError

Really appreciate it. Thank you!

forgot to add () after the goal.