ros - 在ROS中编译自定义消息时出现以下错误

Question

我正在关注有关如何创建 ROS 自定义消息的“WS Newman”教程。编译时出现以下错误“消息/服务'example_msg/Num'的依赖关系已更改。请重新运行cmake”

Num.msg 有

Header header
int32 demo_int
float64 demo_double

Cmakelists.txt

project(example_msg)

find_package(catkin REQUIRED COMPONENTS
  roscpp
  std_msgs
  message_generation
)
add_message_files(
   FILES
   Num.msg
#   Message2.msg
)
generate_messages(
 DEPENDENCIES
 std_msgs
 )
catkin_package(

CATKIN_DEPENDS message_runtime
)
include_directories(
  include ${catkin_INCLUDE_DIRS}
# include
  ${catkin_INCLUDE_DIRS}
)
add_executable(example_ros_message_publisher
  src/example_ros_message_publisher.cpp
)
add_dependencies(example_ros_message_publisher ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
target_link_libraries(example_ros_message_publisher
  ${catkin_LIBRARIES}
)

包.xml

<package format="2">
  <name>example_msg</name>
  <version>0.0.0</version>
  <description>The example_msg package</description>
    <maintainer email="asiri@todo.todo">asiri</maintainer>
  <license>TODO</license>
    <build_depend>message_generation</build_depend>
     <exec_depend>message_runtime</exec_depend> 
   <buildtool_depend>catkin</buildtool_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>std_msgs</build_depend>
  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>
  <exec_depend>roscpp</exec_depend>
  <exec_depend>std_msgs</exec_depend>
  <export>
     </export>
</package>

example_ros_message_publisher.cpp

#include <ros/ros.h>
#include <example_msg/Num.h>
#include <math.h>

int main(int argc, char **argv) {
    ros::init(argc, argv, "example_ros_message_publisher"); // name of this node 
    ros::NodeHandle n; // two lines to create a publisher object that can talk to ROS
    ros::Publisher my_publisher_object = n.advertise<example_msg::Num>("example_topic", 1);
    //"example_topic" is the name of the topic to which we will publish
    // the "1" argument says to use a buffer size of 1; could make larger, if expect network backups

    example_msg::Num  my_new_message;
    //create a variable of type "example_msg", 
    // as defined in this package

   ros::Rate naptime(1.0); //create a ros object from the ros “Rate” class; 
   //set the sleep timer for 1Hz repetition rate (arg is in units of Hz)

   // put some data in the header.  Do: rosmsg show std_msgs/Header
   //  to see the definition of "Header" in std_msgs
    my_new_message.header.stamp = ros::Time::now(); //set the time stamp in the header;
    my_new_message.header.seq=0; // call this sequence number zero
    my_new_message.header.frame_id = "base_frame"; // would want to put true reference frame name here, if needed for coord transforms
    my_new_message.demo_int= 1;
    my_new_message.demo_double=100.0;

    double sqrt_arg;
    // do work here in infinite loop (desired for this example), but terminate if detect ROS has faulted
    while (ros::ok()) 
    {
       my_new_message.header.seq++; //increment the sequence counter
       my_new_message.header.stamp = ros::Time::now(); //update the time stamp
       my_new_message.demo_int*=2.0; //double the integer in this field
       sqrt_arg = my_new_message.demo_double;
       my_new_message.demo_double = sqrt(sqrt_arg);

        my_publisher_object.publish(my_new_message); // publish the data in new message format on topic "example_topic"
    //the next line will cause the loop to sleep for the balance of the desired period 
        // to achieve the specified loop frequency 
    naptime.sleep(); 
    }
}

当我运行 catkin_make install 时出现以下错误。
“消息/服务'example_msg/Num'的依赖关系已经改变。请重新运行cmake。”

Answer 1

柳絮中的一个错误。
要触发更深层次的重建，您可以触摸 CMakeLists.txt包含您的 example_msg/Num 的包的文件.