Windows编译OpenCV4Android解决undefined reference to std错误

程序员文章站 2023-11-03 23:37:22

OpenCV4Android支持三种使用方式1.Java层调用2.NDK调用动态库（方便，但是会包含整个.so库）3.NDK调用静态库（灵活，比如没有用到机器学习模块，libopencv_ml.a里的代码是不会打包到动态库里的）通过链接静态库的方式使用OpenCV4Android，CMAKE配置如下 ......

opencv4android支持三种使用方式
1.java层调用
2.ndk调用动态库（方便，但是会包含整个.so库）
3.ndk调用静态库（灵活，比如没有用到机器学习模块，libopencv_ml.a里的代码是不会打包到动态库里的）
通过链接静态库的方式使用opencv4android，cmake配置如下

#############################prepare for using of opencv static library####################
#first step to use opencv
set(opencv_static on)
#second step to use opencv
set(opencv_dir c:/sdk/opencv-3.4.2-android-sdk/sdk/native/jni)
#third step to use opencv
find_package(opencv required)
###########################################################################################
##################################################the native-lib shared library############
# 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).
        src/main/cpp/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.
target_link_libraries( # specifies the target library.
        native-lib

        #foutth step to use opencv link opencv
        ${opencv_libs}
        # links the target library to the log library
        # included in the ndk.
        ${log-lib})
######################################################################################

仅仅是新建项目稍稍修改了native-lib.cpp的代码，在函数里用了下opencv的函数

#include <jni.h>
#include <string>
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc_c.h"

extern "c" jniexport jstring jnicall
java_com_example_useprebuiltstaticlibrary_mainactivity_stringfromjni(
        jnienv *env,
        jobject /* this */) {
    std::string hello="hello";
    cv::mat m=cv::mat::eye(3,3,cv_8uc1);
    return env->newstringutf(hello.c_str());
}

编译时却报错

build command failed.
error while executing process c:\sdk\cmake\3.6.4111459\bin\cmake.exe with arguments {--build c:\sdk\demo\useprebuiltstaticlibrary\app\.externalnativebuild\cmake\debug\armeabi-v7a --target native-lib}
[1/2] building cxx object cmakefiles/native-lib.dir/src/main/cpp/native-lib.cpp.o
[2/2] linking cxx shared library ..\..\..\..\build\intermediates\cmake\debug\obj\armeabi-v7a\libnative-lib.so
failed: cmd.exe /c "cd . && c:\sdk\ndk-bundle\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe  --target=armv7-none-linux-androideabi23 --gcc-toolchain=c:/sdk/ndk-bundle/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64 --sysroot=c:/sdk/ndk-bundle/sysroot -fpic -isystem c:/sdk/ndk-bundle/sysroot/usr/include/arm-linux-androideabi -g -dandroid -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -mthumb -mfpu=neon -wa,--noexecstack -wformat -werror=format-security -std=c++11 -std=c++11 -o0 -fno-limit-debug-info  -wl,--exclude-libs,libgcc.a -wl,--exclude-libs,libatomic.a -nostdlib++ --sysroot c:/sdk/ndk-bundle/platforms/android-23/arch-arm -wl,--build-id -wl,--warn-shared-textrel -wl,--fatal-warnings -wl,--fix-cortex-a8 -wl,--exclude-libs,libunwind.a -lc:/sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a -wl,--no-undefined -wl,-z,noexecstack -qunused-arguments -wl,-z,relro -wl,-z,now -shared -wl,-soname,libnative-lib.so -o ..\..\..\..\build\intermediates\cmake\debug\obj\armeabi-v7a\libnative-lib.so cmakefiles/native-lib.dir/src/main/cpp/native-lib.cpp.o  c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_highgui.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_features2d.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_shape.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_imgcodecs.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_ml.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_videoio.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_dnn.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_flann.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_objdetect.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_calib3d.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_video.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_superres.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_photo.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_imgproc.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_stitching.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_videostab.a -llog c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibprotobuf.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_calib3d.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_features2d.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_highgui.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_videoio.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_imgcodecs.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibjpeg-turbo.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibwebp.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibpng.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibtiff.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/liblibjasper.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libilmimf.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_flann.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_video.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_photo.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_imgproc.a c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a -lz c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libtbb.a -lc c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libcpufeatures.a -ldl -lm -llog c:/sdk/opencv-3.4.2-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libtegra_hal.a -latomic -lm "c:/sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++_static.a" "c:/sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++abi.a" "c:/sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libunwind.a" "-ldl" && cd ."
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*) [clone .part.13]: error: undefined reference to 'std::basic_ios<char, std::char_traits<char> >::clear(std::_ios_iostate)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::basic_stringstream<char, std::char_traits<char>, std::allocator<char> >::basic_stringstream(std::_ios_openmode)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, int)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, int)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::ostream::put(char)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::ostream::flush()'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, int)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, int)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(system.cpp.o):system.cpp:function cv::exception::formatmessage(): error: undefined reference to 'std::ostream::put(char)'
.
.
.
.
.
.
.
.
.
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(persistence_json.cpp.o):persistence_json.cpp:function icvjsonparsevalue(cvfilestorage*, char*, cvfilenode*): error: undefined reference to 'std::string::at(unsigned int)'
c:/sdk/opencv-3.4.2-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a(persistence.cpp.o):persistence.cpp:function check_if_write_struct_is_delayed(cvfilestorage*, bool): error: undefined reference to 'std::string::assign(char const*, unsigned int)'
clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

google得知是因为编译这些静态库时所用的编译器、标准库等跟ndk当前的版本不同。网上的建议都是stl改为gnustl_static或gnustl_shared之类。可较新的ndk都不支持这些stl了，为了使用opencv静态库只能重新编译了。
编译opencv4android的过程里爬了不少坑，总结一下，希望有助于小白们。

1. 安装mingw
这里不详细的说了，网上很多教程。选择如图三项安装