Category Archives: Language

1、新建工程，在工程根目录找到local.properties文件

sdk.dir=C\:/Languages/Android/android-sdk-windows
ndk.dir=C\:/Languages/Android/android-ndk-r10

2、在app\build.gradle文件中的defaultConfig段内增加

       ndk {
            moduleName "yourModuleName"
       }

2、在工程的app\src\main目录下，新增jni文件夹，将你的ndk工程拷进去

3、在app\src\main\java目录下，将你的java文件拷贝进去

4、如果你的ndk工程用到了其他so文件，在app目录下，新建jniLibs文件夹，将so文件拷贝进去

jniLibs\armeabi\xxx.so
jniLibs\armeabi-v7a\xxx.so
....

5、自定义文件夹路径。编辑app\build.gradle文件下的android段

    //自定义引用库路径
    sourceSets.main {
        jniLibs.srcDir 'src/main/cpplibs'
    }

    //自定义源码路径
    sourceSets.main {
        jni.srcDirs 'src/main/cpp'
    }

6、现在就可以用啦

7、另一种方式就是，先把so文件用命令行生成好，然后，android项目中直接引用so文件就好了

PS：
如果你的ndk项目只有一个c文件，用早期的AndroidStudio编译会报错：

make.exe: *** No rule to make target
......

Execution failed for task ':XXXXXX:compileXXXXXXDebugNdk'.
.......

这样的话，在你的c文件目录下，随便建立一个空的c文件，重新编译就好了，好挫。

准备工作
1、下载NDK
2、直接运行，会解压到当前文件夹
3、剪切到你喜欢的文件夹

第一个项目
1、写一个调用JNI的Java类

package com.neohope.android.jni;

public class JniFunc {
    private native int  addNative(int a, int b);

    static {
        System.loadLibrary("jnifunc");
    }

    public int add(int a, int b)
    {
        return addNative(a,b);
    }
}

2、用你喜欢的方式，编译为class文件

3、用jdk的javah工具生成头文件

#在class文件的顶层路径，比如这个例子，就在com这个文件夹相同目录下
javah com.neohope.android.jni.JniFunc

会输出文件“com_neohope_android_jni_JniFunc.h”：

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_neohope_android_jni_JniFunc */

#ifndef _Included_com_neohope_android_jni_JniFunc
#define _Included_com_neohope_android_jni_JniFunc
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     com_neohope_android_jni_JniFunc
 * Method:    addNative
 * Signature: (II)I
 */
JNIEXPORT jint JNICALL Java_com_neohope_android_jni_JniFunc_addNative
  (JNIEnv *, jobject, jint, jint);

#ifdef __cplusplus
}
#endif
#endif

4、编写“com_neohope_android_jni_JniFunc.c”

#include <jni.h>
#include "com_neohope_android_jni_JniFunc.h"

JNIEXPORT jint JNICALL Java_com_neohope_android_jni_JniFunc_addNative
  (JNIEnv *evn, jobject obj, jint a, jint b)
{
    return a+b;
}

5、编写Android.mk及Application.mk

APP_ABI := all

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE    := jnifunc
LOCAL_SRC_FILES := com_neohope_android_jni_JniFunc.c \

LOCAL_C_INCLUDES += com_neohope_android_jni_JniFunc.h

include $(BUILD_SHARED_LIBRARY)

6、编译

SET NDK_HOME="C:\Languages\Android\android-ndk-r10d"

SET PATH=%NDK_HOME%;%PATH%

CMD

REM ndk-build

    private BaiduMap mBaiduMap = null;
    private MapView mMapView = null;
    private LocationClient mLocClient = null;
    private MyLocationConfiguration.LocationMode mCurrentMode;
    private Boolean isFirstLoc = true;
    private BitmapDescriptor mCurrentMarker=null;

    private float[] accelerometerValues=new float[3];
    private float[] magneticFieldValues=new float[3];
    private float[] values=new float[3];
    private float[] rotate=new float[9];
    private float[] degree=new float[3];

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

        SensorManager sm = (SensorManager) getApplicationContext().getSystemService(Context.SENSOR_SERVICE);
        SensorEventListener sensorEventListener = new SensorEventListener() {
            @Override
            public void onSensorChanged(SensorEvent event) {
                if(event.sensor.getType()==Sensor.TYPE_ACCELEROMETER){
                    accelerometerValues=event.values;
                }
                if(event.sensor.getType()==Sensor.TYPE_MAGNETIC_FIELD){
                    magneticFieldValues=event.values;
                }
                else
                {
                    return;
                }

                SensorManager.getRotationMatrix(rotate, null, accelerometerValues, magneticFieldValues);
                SensorManager.getOrientation(rotate, values);

                //rotate
                degree[0] = values[0]/3.1415926f*180;
                //up down
                degree[1] = values[1]/3.1415926f*180;
                //left right
                degree[2] = values[2]/3.1415926f*180;
            }

            @Override
            public void onAccuracyChanged(Sensor sensor, int accuracy) {
            }
        };

        sm.registerListener(sensorEventListener,sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),SensorManager.SENSOR_DELAY_NORMAL);
        sm.registerListener(sensorEventListener,sm.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),SensorManager.SENSOR_DELAY_NORMAL);

        // init baiduMap
        mMapView = (MapView) findViewById(R.id.dbmapView);
        mBaiduMap = mMapView.getMap();

        // set parameters
        mCurrentMode = MyLocationConfiguration.LocationMode.FOLLOWING;
        mCurrentMarker=null;
        mBaiduMap.setMyLocationConfigeration(new MyLocationConfiguration(mCurrentMode, true, mCurrentMarker));

        // allow loaction
        mBaiduMap.setMyLocationEnabled(true);
        mLocClient = new LocationClient(this);
        mLocClient.registerLocationListener(new MyLocationListenner());
        LocationClientOption option = new LocationClientOption();
        option.setOpenGps(true);
        option.setCoorType("bd09ll");
        option.setScanSpan(1000);
        mLocClient.setLocOption(option);
        mLocClient.start();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mMapView.onDestroy();
    }

    public class MyLocationListenner implements BDLocationListener {
        @Override
        public void onReceiveLocation(BDLocation location) {
            if (location == null || mMapView == null)
                return;

            MyLocationData locData = new MyLocationData.Builder()
                    .accuracy(location.getRadius())
                    .direction(degree[0])
                    .latitude(location.getLatitude())
                    .longitude(location.getLongitude()).build();
            mBaiduMap.setMyLocationData(locData);

            if (isFirstLoc) {
                isFirstLoc = false;
                LatLng ll = new LatLng(location.getLatitude(),
                        location.getLongitude());
                MapStatusUpdate u = MapStatusUpdateFactory.newLatLng(ll);
                mBaiduMap.animateMapStatus(u);
            }
        }
    }