第一步：创建so库

 

第二步：看一下Native的项目结构

自动生成引用文件build.gradle（app）

   externalNativeBuild {
        cmake {
            path file('src/main/cpp/CMakeLists.txt')
            version '3.22.1'
        }
    }
//每个版本的开发工具不一样 我这个是自动生成的so库文件类型，尽量用新版ASK开发工具

CMakeLists.txt

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html.
# For more examples on how to use CMake, see https://github.com/android/ndk-samples.

# Sets the minimum CMake version required for this project.
cmake_minimum_required(VERSION 3.22.1)

# Declares the project name. The project name can be accessed via ${ PROJECT_NAME},
# Since this is the top level CMakeLists.txt, the project name is also accessible
# with ${CMAKE_PROJECT_NAME} (both CMake variables are in-sync within the top level
# build script scope).
project("sodemo")

# 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.
#
# In this top level CMakeLists.txt, ${CMAKE_PROJECT_NAME} is used to define
# the target library name; in the sub-module's CMakeLists.txt, ${PROJECT_NAME}
# is preferred for the same purpose.
#
# In order to load a library into your app from Java/Kotlin, you must call
# System.loadLibrary() and pass the name of the library defined here;
# for GameActivity/NativeActivity derived applications, the same library name must be
# used in the AndroidManifest.xml file.
add_library(${CMAKE_PROJECT_NAME} SHARED
        # List C/C++ source files with relative paths to this CMakeLists.txt.
        native-lib.cpp
        src/NativeImpl.cpp)

# Specifies libraries CMake should link to your target library. You
# can link libraries from various origins, such as libraries defined in this
# build script, prebuilt third-party libraries, or Android system libraries.
target_link_libraries(${CMAKE_PROJECT_NAME}
        # List libraries link to the target library
        android
        log)

native-lib.cpp

#include <jni.h>
#include <string>
#include "src/NativeImpl.h"

/* 获取NativeImpl */
NativeImpl nativeImpl;

NativeImpl *getNativeImpl() {
    return &nativeImpl;
}

extern "C"
JNIEXPORT jstring JNICALL
Java_com_geek_sodemo_NativeImpl_ICC_1interface_1power(JNIEnv *env, jclass clazz) {
    // TODO: implement ICC_interface_power()
    // TODO: implement getUserName()
    char *c = getNativeImpl()->ICC_interface_power();
    return env->NewStringUTF(c);
}

第三步：直接加上so库代码优化(不废话)

把native-lib.cpp分离出来创建 .h和.cpp文件 如下代码

NativeImpl.cpp

#include "NativeImpl.h"


NativeImpl::NativeImpl() {

}

NativeImpl::~NativeImpl() {

}

char *NativeImpl::ICC_interface_power() {
    // 这里处理代码逻辑
    return "卡槽上下电控制";
}

NativeImpl.h

#ifndef MYNATIVE_CLIENTIMPL_H
#define MYNATIVE_CLIENTIMPL_H

#include <vector>

class NativeImpl {
public:
    NativeImpl();
    virtual ~NativeImpl();

    virtual char* ICC_interface_power();
};


#endif //MYNATIVE_CLIENTIMPL_H

第四步:在CMakeLists.txt文件中增加cpp引入

add_library(${CMAKE_PROJECT_NAME} SHARED
        # List C/C++ source files with relative paths to this CMakeLists.txt.
        native-lib.cpp
        src/NativeImpl.cpp)

native-lib.cpp增加方法

#include <jni.h>
#include <string>
#include "src/NativeImpl.h"

/* 获取NativeImpl */
NativeImpl nativeImpl;

NativeImpl *getNativeImpl() {
    return &nativeImpl;
}

extern "C"
JNIEXPORT jstring JNICALL
Java_com_geek_sodemo_NativeImpl_ICC_1interface_1power(JNIEnv *env, jclass clazz) {
    // TODO: implement ICC_interface_power()
    // TODO: implement getUserName()
    char *c = getNativeImpl()->ICC_interface_power();
    return env->NewStringUTF(c);
}

第五步:so库使用优化NativeImpl创建在应用的目录结构下

public class NativeImpl {

    // 加载so库
    static {
        System.loadLibrary("sodemo");
    }
    /**
     * 添加 native 方法
     */
    public static native String ICC_interface_power();
}

MainActivity.class中进行引用

public class MainActivity extends AppCompatActivity {


    private ActivityMainBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        // Example of a call to a native method
        TextView tv = binding.sampleText;
        tv.setText(NativeImpl.ICC_interface_power());
    }


}

最后运行看结果

上面的内容生成so库及给java代码调用就完成了

下面是怎样是这个so库给其他应用使用  如下

然后拷贝.so文件到 新创建的项目中的libs文件下 

 在build.gradle 里面android节点下增加

sourceSets {
    main {
        jniLibs.srcDirs = ['libs']
    }
}