我正在尝试链接 Android Studio 2.2 中的 opencv native 库。我找到的所有关于此的主题都使用 Android.mk 文件或 build.gradle 文件中的其他方法,Android Studio 找不到。
我正在使用 Android Studio 2.2 并通过创建一个支持 C++ 的新项目来创建项目。
到目前为止,我已成功将 OpenCV 库包含在 C++ 源文件中:
#include <jni.h>
#include <string>
#include "opencv.hpp"
extern "C"
jstring
Java_com_rvstudios_roomscanner_capp_MainActivity_stringFromJNI(
JNIEnv *env,
jobject /* this */) {
std::string hello = "Hello from C++";
cv::Mat image;
cv::cvtColor(image, image, CV_BGR2GRAY);
return env->NewStringUTF(hello.c_str());
}
当我尝试构建它时,我在 opencv 函数上遇到 undefined reference 错误,这是因为必须链接静态库(.a 文件)。根据我已经阅读的内容,这应该在 build.gradle 文件中完成。
到目前为止,这是我的 build.gradle 文件:
apply plugin: 'com.android.application'
def targetPlatform = "mips"
android {
compileSdkVersion 23
buildToolsVersion "25.0.1"
defaultConfig {
applicationId "com.rvstudios.roomscanner.capp"
minSdkVersion 18
targetSdkVersion 23
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags ""
cppFlags.add("-isystem${project.rootDir}/app/src/main/cpp/vision".toString())
}
}
}
sourceSets.main {
jni.srcDirs = ["${project.rootDir}/app/src/main/jniLibs/${targetPlatform.toString()}/"]
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:design:23.4.0'
testCompile 'junit:junit:4.12'
}
我被困在这里是因为我不知道如何链接静态库。我已经看过很多关于同一问题的 SO 主题,但我读到的所有内容都使用不同的项目设置,而且我是 Android 开发的新手,所以我对此一无所知。
编辑1: 我的 CMakeLists.txt:
# Sets the minimum version of CMake required to build the native
# library. You should either keep the default value or only pass a
# value of 3.4.0 or lower.
cmake_minimum_required(VERSION 3.4.1)
# 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 it 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).
# Associated headers in the same location as their source
# file are automatically included.
src/main/cpp/native-lib.cpp
src/main/cpp/vision/opencv.hpp )
# Searches for a specified prebuilt library and stores the path as a
# variable. Because system libraries are included 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 the
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib}
)
最佳答案
在 CMakeLists.txt 中,添加:
set(pathToOpenCV /Users/admin/Projects/OpenCV-android-sdk/sdk/native/) // Replace with your OpenCV SDK path
include_directories(${pathToOpenCV}/jni/include)
关于c++ - Android Studio 2.2链接opencv静态库,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40843117/