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我正在运行 Ubuntu 18。我想将我编写的 c++ 脚本转换为 android 应用程序。我看到 Android 应用程序也可以运行 c++ 脚本。我的脚本依赖于 PCL（点云库）、CGAL 和 TBB。作为第一步，我想确保我可以在 android studio 中制作一个依赖于 PCL 的 c++ 脚本。我按照本教程创建了一个使用简单 c++ 脚本的 android 应用程序。接下来我想在该脚本中使用点云库。作为第一步，我修改了 CMakeList.txt，这就是问题开始的地方......

目前我的 CMakeList.txt 文件如下所示：

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html

# Sets the minimum version of CMake required to build the native library.

cmake_minimum_required(VERSION 3.4.1)

# Declares and names the project.

project("cmaketest")

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             native-lib.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.

set(PCL_DIR "/usr/lib/x86_64-linux-gnu/cmake/pcl")
find_package(PCL 1.2 REQUIRED)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} ${PCL_LIBRARIES})

我已经用这个例子验证了我的 PCL 安装，一切正常。这是用于验证的 CMakeList.txt：

cmake_minimum_required(VERSION 2.8 FATAL_ERROR)

project(pcd_write)

find_package(PCL 1.2 REQUIRED)

include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

add_executable (pcd_write pcd_write.cpp)
target_link_libraries (pcd_write ${PCL_LIBRARIES})

但在 Android Studio 中，我收到一个错误，即找不到 eigen：

Execution failed for task ':app:generateJsonModelDebug'.
> error when building with cmake using /home/dan/AndroidStudioProjects/CmakeTest/app/src/main/cpp/CMakeLists.txt: Build command failed.
  Error while executing process /home/dan/Android/Sdk/cmake/3.6.4111459/bin/cmake with arguments {-H/home/dan/AndroidStudioProjects/CmakeTest/app/src/main/cpp -DCMAKE_CXX_FLAGS=-std=c++17 -DCMAKE_FIND_ROOT_PATH=/home/dan/AndroidStudioProjects/CmakeTest/app/.cxx/cmake/debug/prefab/x86/prefab -DCMAKE_BUILD_TYPE=Debug -DCMAKE_TOOLCHAIN_FILE=/home/dan/Android/Sdk/ndk/21.4.7075529/build/cmake/android.toolchain.cmake -DANDROID_ABI=x86 -DANDROID_NDK=/home/dan/Android/Sdk/ndk/21.4.7075529 -DANDROID_PLATFORM=android-19 -DCMAKE_ANDROID_ARCH_ABI=x86 -DCMAKE_ANDROID_NDK=/home/dan/Android/Sdk/ndk/21.4.7075529 -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_LIBRARY_OUTPUT_DIRECTORY=/home/dan/AndroidStudioProjects/CmakeTest/app/build/intermediates/cmake/debug/obj/x86 -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=/home/dan/AndroidStudioProjects/CmakeTest/app/build/intermediates/cmake/debug/obj/x86 -DCMAKE_MAKE_PROGRAM=/home/dan/Android/Sdk/cmake/3.6.4111459/bin/ninja -DCMAKE_SYSTEM_NAME=Android -DCMAKE_SYSTEM_VERSION=19 -B/home/dan/AndroidStudioProjects/CmakeTest/app/.cxx/cmake/debug/x86 -GNinja}
  -- Could NOT find eigen (missing:  EIGEN_INCLUDE_DIRS) 
  -- Configuring incomplete, errors occurred!
  See also "/home/dan/AndroidStudioProjects/CmakeTest/app/.cxx/cmake/debug/x86/CMakeFiles/CMakeOutput.log".

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

我不明白为什么 pcl 可以在常规项目中找到，但不能在 android studio 项目中找到，因为我在 CMakeList.txt 中使用了相同的行？CMakeList.txt 文件在 Android Studio 中的处理方式是否存在差异？我还必须为我的 pcl 库添加一个直接路径，以便它使用 Android Studio 找到 pcl，这在常规项目中是不需要的。（我用这条线做到了set(PCL_DIR "/usr/lib/x86_64-linux-gnu/cmake/pcl")：）

有任何想法吗？

谢谢！

丹尼尔

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0 回答 0