Android Studio JNI开发-CMake方式

Android Studio 开发jni所需插件:

如下图所示：

ndk-plugin.png

开发过程

1、创建项目需要注意

选择include.png

C++支持选择.png

c3.png

# 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.

add_library( # Sets the name of the library.
             #(1) 自定义so文件名称，可以自定义修改
             fm

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
            #(3)如果新增.cpp/.c文件时，需要手动在下面添加对应的文件全路径
             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.
                       # (2)自定义so文件名称，可以自定义修改
                       fm

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

如上面的文本所示：
（1）和（2）位置，如果需要自定义名称时，需要都修改；
（3）位置，如果新增.cpp/.c文件需要手动注册；
3、编译查看生成的.so文件
如下图所示：

c5.png

package fmblzf.cmakejni.ndk;

/**
 * Created by Administrator on 2017/5/25.
 */

public class CMakeNative {

    /**
     * 静态加载.so文件
     * 注意加载的so文件名称和build.gradle中的moduleName保持一致
     * 即没有lib前缀的文件名
     */
    static {
        System.loadLibrary("fm");
    }
    /**
     * 测试.so文件链接成功
     * @param str
     * @return
     */
    public static native String test(String str);
}

然后根据创建的类和方法去编写对应的jni代码，和Android Studio JNI开发-1中的操作完全一致，但是不同的是，在编写jni代码的时候友好的代码提示功能是非常有用和方便的。

c6.png

源码下载