ros msg和srv使用

在包文件中新建文件夹srv和msg，在这两个文件夹中新建test.msg，test.srv

修改apckage.xml

添加以下内容

<build_depend>：message_generation 
<run_depend>/<exec_depend>：message_runtime

修改CMakeList.txt

1. find_package()添加构建时依赖message_generation

find_package(catkin REQUIRED COMPONENTS ...message_generation ...)

2. add_message()
   添加.msg文件

add_message_files(
  DIRECTORY msg
  FILES test.msg
)

3. generate_messages()
   生成message头文件，指定依赖

generate_messages(DEPENDENCIES std_msgs)

4. catkin_package()
   添加运行时依赖message_runtime

catkin_package(
  ...
  CATKIN_DEPENDS ... message_runtime ...
  ...)