JNI开发

1. 配置NDK

ndk.dir=E\:\\Andorid_Sdk\\ndk-bundle

 2. 加载so, 声明native函数

 

 3. 创建jni目录， 编写C代码

 

 以下是生成so的关键代码

1. CMake方式

# CMakeLists.txt
# 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.
#CMakeLists.txt
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.
add_library(
      # 设置so文件名称.
       Hello
       # 设置这个so文件为共享.
       SHARED
       # Provides a relative path to your source file(s).
       src/main/jni/hello.c)

# 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.
            # 制定目标库.
            Hello
            # Links the target library to the log library
            # included in the NDK.
            ${log-lib} )

 

 

 内

externalNativeBuild{
            cmake{
                // 指定编译架构 指定需要产出哪些架构平台
                abiFilters 'arm64-v8a','armeabi-v7a','x86','x86_64'
            }
}

 外

externalNativeBuild {
        cmake {
            // 在该文件种设置所要编写的c源码位置，以及编译后so文件的名字
            path 'CMakeLists.txt'
            version "3.18.1"
        }
    }