【catkin】——如何导入一个catkin包的头文件和动态库_农夫山泉2号的博客

1. find_package(catkin）

find_package(catkin REQUIRED COMPONENTS
gflags_catkin
glog_catkin
opencv3_catkin
)
catkin_package()
找的是 /opt/ros/melodic/share/catkin/cmake/ 下的 catkinConfig.cmake
可以在里面打印一些信息
if(catkin_FIND_COMPONENTS)
  foreach(component ${catkin_FIND_COMPONENTS})
    string(TOLOWER "${component}" component_lower)
    # skip catkin since it does not make sense as a component
    if(NOT ${component_lower} STREQUAL "catkin")
      # get search paths from CMAKE_PREFIX_PATH (which includes devel space)
      set(paths "")
      foreach(path ${CMAKE_PREFIX_PATH})
        if(IS_DIRECTORY ${path}/share/${component}/cmake)
          list(APPEND paths ${path}/share/${component}/cmake)
        endif()
      endforeach()
      message("chenjun: ${paths}")					# 可以打印cmake的路径
      # find package component
      if(catkin_FIND_REQUIRED)
        # try without REQUIRED first
        find_package(${component} NO_MODULE PATHS ${paths}
          NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
2. catkin包
 
catkin的包，在cmake文件夹下有package-extras.cmake.in的模板。在里面设定每个catkin包的头文件和动态库。不然上面的find_package(catkin)是无法包含库的头文件和动态库的。 
# This overrides the dependency tracker with the GLOG library file.
set(@PROJECT_NAME@_LIBRARIES 
  @CATKIN_DEVEL_PREFIX@/lib/libglog${CMAKE_SHARED_LIBRARY_SUFFIX})
set(@PROJECT_NAME@_INCLUDE_DIR @CATKIN_DEVEL_PREFIX@/include)
3. 辅助信息变量
 
${opencv3_catkin_LIBRARIES}：具体catkin包的动态库
${catkin_INCLUDE_DIRS}：所有catkin包的头文件
${catkin_LIBRARIES}：所有catkin包的动态库
                    catkin1. find_package(catkin）find_package(catkin REQUIRED COMPONENTSgflags_catkinglog_catkinopencv3_catkin)catkin_package()找的是/opt/ros/melodic/share/catkin/cmake/下的catkinConfig.cmake可以在里面打印一些信息if(catkin_FIND_COMPONENTS)  foreach(component ${ca.
				[小白笔记0]ROS配置环境的问题find_package
find_package(catkin REQUIRED COMPONENTS
message_generation
roscpp
rosconsole
sensor_msgs
cmake_modules REQUIRED
Eigen3 REQUIRED
find_package(OpenCV REQUIRED)
当我把OpenCV ...
				今天catkin build 整个工程，编译catkin_tools_prebuild时遇到失败的情况，如下：
The catkin CMake module was not found, but it is required to build a linked
 workspace. To resolve this, please do one of the following, and ...
				catkin_package与find_packagehttps://cloud.tencent.com/developer/ask/183702
ROS Catkin 教程之 catkin_package(...) 到底在做什么？https://blog.csdn.net/lcc816/article/details/82962561
https://answers.ros.org/quest...
(3)add_executable( src1 src2 ...) （简易写法）
(4)target_link_libraries( lib1 lib2 ...) (简易写法，lib是依赖库的路径)
重点的命令总结： ...
				While looking at a CMakeLists.txt file, I was wondering the exact meaning of the CATKIN_DEPENDS option of the catkin_package(...) macro was.
I would expect to see there the same packages as listed in ...
				1.错误：在catkin build cv_bridge这步时，遇到错误
CMake Error at /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
 Could not find a package configuration file provided by "opencv3_catkin"
 with any of the following names:
  opencv3_catkin...
CMake Error at cmake/OpenCVCompilerOptions.cmake:21 (else):
Flow control statements are not properly nested.
打开对应的cmake文件21行发现同一个作用域有两个else
21行22行注释掉就可以了
别的电脑也编译过貌似没出现过这种问题，应该与cmake版本有关
voxblox++是2019年ETHZ的RAL论文Volumetric Instance-Aware Semantic Mapping and 3D Object Discovery所提出的全景建图算法，是在voxblox基础上改进的，增加了实例和语义信息。因为感觉效果不错，所以想复现一下看看能不能作为之后工作的基础。
基本上是参考着官方教程来的
官方安装编译教程
官方运行教程
还有这一篇博客是找到的唯一一个介绍了编译过程的，很多东西都用到了他的，非常感谢
参考编译教程
大环境准备
catkin编译过程：
1．查找workspace(catkin_ws)下的src的package
2.   catkin编译系统依据 Cmakelists.txt 和 package.xml 文件，生成 makefiles(catkin_ws/build/)
3.   make  makefiles文件，生成可执行文件 (放在catkin_ws/devel中)
cakin 相当于cmake 和 make 的封装完成编译的工具
命令：catkin_make
mkdir -p ~/catk
				在 ROS 功能包的 CMakeLists.txt 文件中有这样两个宏，catkin_package 与 find_package。例如它们具有以下内容：
find_package(catkin REQUIRED COMPONENTS
    roscpp
    actionlib
    std_msgs
    message_generation
    actionlib_msgs
注释：这一点与Python很像都是使用“#”作为注释符
	变量：在CMake中变量的定义有些特别，一般用set命令作为显式定义和变量的赋值。注意：如果在if语句中使用到变量时可以直接使用变量名，如果不是在if语句中使用的话则需要使用${}来引用变量。
	调用命令：命令不分大小写，参数使用空格分隔，如果参数中出现空格则需要用双引号包含起来
package....