在现有AS项目中新增OpenCV|在现有AS项目中新增OpenCV c++库的支持
环境
- AS 3.4.1
- CMake 版本，AS上查不到，只显示了 installed.由 AS 安装
- AS 切换到 project 目录下
- 进入目录 app--src，右键 src，新建 Directory.命名为 cpp
- 右键 cpp文件夹，新建 cpp文件，命名为 test-cpp-lib.cpp
- 右键 cpp文件夹，新建 CMakeLists.txt 文件
- CMakeLists.txt 文件填入内容
# 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)# 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.# 定义自己写的库
add_library( # Sets the name of the library.
test-cpp-lib# Sets the library as a shared library.
SHARED# Provides a relative path to your source file(s).
test-cpp-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.# 如果需要其他NDK原生库的话，可自行在此处添加
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)target_link_libraries( # Specifies the target library.
test-cpp-lib# Links the target library to the log library
# included in the NDK.
${log-lib})
CMake配置不在本文范围之内
- 进入 app 对应的 build.gradle，做以下操作
- 在defaultconfig 块下新增
externalNativeBuild { cmake { cppFlags "-std=c++14 -fexceptions -frtti" arguments "-DANDROID_ARM_NEON=TRUE",'-DANDROID_STL=c++_shared' // abi过滤 abiFilters 'armeabi-v7a','arm64-v8a' } } // abi过滤 ndk { abiFilters 'armeabi-v7a','arm64-v8a' }
- 在defaultconfig 块下新增
- 【在现有AS项目中新增OpenCV|在现有AS项目中新增OpenCV c++库的支持】在android块下新增
// c/c++源码位置 sourceSets { main { jni.srcDirs = ['src/main/cpp'] jniLibs.srcDirs = ['src/main/jniLibs/libs'] } } externalNativeBuild { cmake { path "src/main/cpp/CMakeLists.txt" version "3.10.2" } }
- 注意相应的路径，不要照抄。
- 此时应该已经完成了 c++ 的接入配置，以下为验证手段。
- 在src-main-java 文件夹内新建 java 文件，命名为 JNITools.java
package xyz.jimbray.demo;
public class JNITools {static {
System.loadLibrary("test-cpp-lib");
}public static native String getHelloString();
}
- 如果已经配置成功，AS现在会在 getHelloString 函数处提示错误，AS这个版本已经支持直接跳转到 cpp 文件新建对应函数。
- 但是我试的时候，出现直接跳转到一个 自动新建的 test-cpp-lib.c 文件，无视我自建的 cpp 文件，还报错。
- 我把 c 文件的内容直接复制到 cpp 文件，删除 c 文件，就可以了。
- 目前调用成功，不再用代码演示调用过程。
