第一章项目导入

1.1建立工作空间myMake、导入功能包ros_tutorials

mkdir -p ～/myCmake/src
cd ～/myCmake/src
git clone https://github.com/ros/ros_tutorials.git

将myCmake工作空间-ros_tutorials包内的乌龟节点保留，其他删除；

cd   ～/myCmake/src/ros_tutorials
rm -rf ros*

因为导入的ros_tutorials目录内存在四个应用包：

因此，删除前三个，保留turtlesim一个功能包。

进入乌龟功能包目录，用tree -L 2 语句显示内涵路径，全部内容如下：

.
├── CHANGELOG.rst
├── CMakeLists.txt
├── images    # 相关的图片文件
├── include   # 相关的头文件
├── launch    # 运行时文件 用roslaunch调用
├── msg       # 消息数据结构定义（传递用）
├── package.xml   # 包结构定义
├── src           # cpp程序代码
├── srv           # 服务消息数据结构定义（传递用）
└── tutorials     # 共有的程序函数

更详细的包内信息是：

├── CHANGELOG.rst
├── CMakeLists.txt
├── images
│   ├── box-turtle.png
│   ├── diamondback.png
         ... ... ...
│   └── turtle.xar
├── include
│   └── turtlesim
│       ├── turtle_frame.h
│       └── turtle.h
├── launch
│   └── multisim.launch
├── msg
│   ├── Color.msg
│   └── Pose.msg
├── package.xml
├── src
│   ├── turtle.cpp
│   ├── turtle_frame.cpp
│   ├── turtlesim
│   │   └── __init__.py
│   └── turtlesim.cpp
├── srv
│   ├── Kill.srv
│   ├── SetPen.srv
│   ├── Spawn.srv
│   ├── TeleportAbsolute.srv
│   └── TeleportRelative.srv
└── tutorials
    ├── draw_square.cpp
    ├── mimic.cpp
    └── teleop_turtle_key.cpp

1.2 打开CMakeLists.txt查看对应的代码

cmake_minimum_required(VERSION 3.0.2)?? -----指定cmake最低版本3。02
project(turtlesim) --------指定工程名称“turtlesim”

find_package(catkin REQUIRED COMPONENTS geometry_msgs message_generation rosconsole roscpp roscpp_serialization roslib rostime std_msgs std_srvs)

-----告诉catkin所依赖的组件清单

find_package(Qt5Widgets REQUIRED)

----------指定依赖于QT5Widgets【主要从环境的PATH变量查找，较为智能，比如遇到bin结尾的路径，将自动回到上一级路径查找。】
find_package(Boost REQUIRED COMPONENTS thread)

include_directories(include ${catkin_INCLUDE_DIRS} ${Boost_INCLUDE_DIRS})

---------------指定include路径的列表
link_directories(${catkin_LIBRARY_DIRS})

---------------------指定静态库的列表

add_message_files(DIRECTORY msg FILES? Color.msg Pose.msg)

add_service_files(DIRECTORY srv FILES
????????????????? Kill.srv
????????????????? SetPen.srv
????????????????? Spawn.srv
????????????????? TeleportAbsolute.srv
????????????????? TeleportRelative.srv)
generate_messages(DEPENDENCIES geometry_msgs std_msgs std_srvs)

catkin_package(CATKIN_DEPENDS geometry_msgs message_runtime std_msgs std_srvs)

set(turtlesim_node_SRCS
? src/turtlesim.cpp
? src/turtle.cpp
? src/turtle_frame.cpp
)
set(turtlesim_node_HDRS
? include/turtlesim/turtle_frame.h
)

qt5_wrap_cpp(turtlesim_node_MOCS ${turtlesim_node_HDRS})

add_executable(turtlesim_node ${turtlesim_node_SRCS} ${turtlesim_node_MOCS})
target_link_libraries(turtlesim_node Qt5::Widgets ${catkin_LIBRARIES} ${Boost_LIBRARIES})
add_dependencies(turtlesim_node turtlesim_gencpp)

add_executable(turtle_teleop_key tutorials/teleop_turtle_key.cpp)
target_link_libraries(turtle_teleop_key ${catkin_LIBRARIES})
add_dependencies(turtle_teleop_key turtlesim_gencpp)
add_executable(draw_square tutorials/draw_square.cpp)
target_link_libraries(draw_square ${catkin_LIBRARIES} ${Boost_LIBRARIES})
add_dependencies(draw_square turtlesim_gencpp)
add_executable(mimic tutorials/mimic.cpp)
target_link_libraries(mimic ${catkin_LIBRARIES})
add_dependencies(mimic turtlesim_gencpp)

install(TARGETS turtlesim_node turtle_teleop_key draw_square mimic
? RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION})

install(DIRECTORY images
? DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
? FILES_MATCHING PATTERN "*.png" PATTERN "*.svg")