opencv - 子目录中的CMake文件无法访问外部库

Question

我的项目结构如下:

Project
  | Dependency
      functions.cpp
      functions.h
  | DisplayImage.cpp

我想在functions.cpp中使用opencv。当我在DisplayImage中使用opencv函数时，它可以工作，但是当我在functions.h中包含opencv2 / imgproc.hpp时，出现“找不到文件错误”。

我的CMakeLists在根目录中看起来像这样:

cmake_minimum_required(VERSION 3.10)

project(DisplayImage)

set("OpenCV_DIR" "~/opencv/build")
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(OpenCV REQUIRED)

add_subdirectory(Dependency)

add_executable(DisplayImage DisplayImage.cpp)

target_link_libraries(DisplayImage ${OpenCV_LIBS})

include_directories("${CMAKE_SOURCE_DIR}/Dependency")
include_directories("~/CppLibraries/eigen-3.3.7/Eigen")

并且Dependency目录中的CMakeLists.txt文件包含:

add_library(Dependency functions.cpp functions.h)

为什么在functions.h中找不到opencv2 / imgproc.hpp？

这是我收到的错误消息:

$ cmake --build .
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/bn/Documents/C++/opencv_playground/build
Scanning dependencies of target DisplayImage
[ 25%] Building CXX object CMakeFiles/DisplayImage.dir/DisplayImage.cpp.o
[ 50%] Linking CXX executable DisplayImage
[ 50%] Built target DisplayImage
[ 75%] Building CXX object Dependency/CMakeFiles/Dependency.dir/functions.cpp.o
In file included from /Users/bn/Documents/C++/opencv_playground/Dependency/functions.cpp:1:
/Users/bn/Documents/C++/opencv_playground/Dependency/functions.h:1:10: fatal error: 'opencv2/imgproc.hpp'
      file not found
#include <opencv2/imgproc.hpp>
         ^~~~~~~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [Dependency/CMakeFiles/Dependency.dir/functions.cpp.o] Error 1
make[1]: *** [Dependency/CMakeFiles/Dependency.dir/all] Error 2
make: *** [all] Error 2

Answer 1

为了调试目的，您可以在“find_package(OpenCV REQUIRED)”之后的CMakeLists.txt中添加以下行。

message(STATUS "cv libs: ${OpenCV_LIBS}")
message(STATUS "include_path: ${OpenCV_INCLUDE_DIRS}")

当您执行“cmake。”时，在终端中，它将打印出所有opencv库并包含路径。