Android studio Jni调用第三方库（CMakelist）

Jni项目生成的库文件需要调用硬件给的c++编写的so库，拿到so库跟头文件，jni通过CMakelist方式怎么调用c++写的so文件。。。

 

首先，创建项目，勾选support c/c++选项

接下来，就是配置CMakeList.text文件：

下面附上CMakeList的详细代码：

# 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)

#引用已经有的库
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 )

#资源文件夹的位置libs
set(distribution_DIR ${CMAKE_SOURCE_DIR}/../../../../libs)

#导入类库,只是作为引用,不编译
add_library( first
             SHARED
             IMPORTED )

#引用目标类库是本地类库位置在libs/armeabi-v7a/xxx.so
set_target_properties( first
                       PROPERTIES IMPORTED_LOCATION
                       ../../../../libs/armeabi-v7a/libfirst.so )

#添加类库位置在src/main/cpp/xxx.cpp需要编译
add_library(native-lib
             SHARED
             src/main/cpp/native-lib.cpp )

#引入头文件目录位置
include_directories(libs/jpeg)

#将预构建库与你本地库相关联
target_link_libraries( # Specifies the target library.
                       native-lib first

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

然后点击MakeProject：

这时，如果没出什么意外的话，我们可以在 t\app\build\intermediates\cmake\debug\obj 下查看到生成的so文件

我们的Android项目即可调用此库做相应的操作了

但是要注意一点，因为我们的libnative-lib.so是依赖libfirst.so生成的，所以我们调用的时候需要将两个库都加载进去，不然会报错

public class MainActivity extends AppCompatActivity {

    // Used to load the 'native-lib' library on application startup.
    static {
        System.loadLibrary("first");
        System.loadLibrary("native-lib");
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Example of a call to a native method
        TextView tv = (TextView) findViewById(R.id.sample_text);
        tv.setText(helloString("hi   kathy"));
    }

    /**
     * A native method that is implemented by the 'native-lib' native library,
     * which is packaged with this application.
     */
    public native String stringFromJNI();

    public native String helloString(String hello);

}

效果如图：

ok，that is all

不懂的可以下载相应的demo自行查看

有关其他的jni问题可以提出来相互讨论，刚刚接触，共同学习，共同进步

thanks~

DEMO下载：http://download.csdn.net/download/qq_35532751/10138080