Android Studio2.2.2 配置NDK

編輯：關於Android編程

環境

主機:WIN 7
開發環境:Android Studio2.2.2

步驟

安裝NDK
打開Tools->Android->SDK Manager->SDK Tools選中LLDB和NDK，點擊確認，軟件會自動安裝NDK。

配置環境變量

增加一項：NDK_ROOT，如：C:\soft\adt-bundle-windows-x86-20130911\sdk\ndk-bundle
在path中增加%NDK_ROOT%
安裝完記得重啟
在main中新建文件夾jni

新建hello-jni.c
函數需按照規則命名：Java_包名類名方法名

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
#include 
#include 

/* This is a trivial JNI example where we use a native method
 * to return a new VM String. See the corresponding Java source
 * file located at:
 *
 *   apps/samples/hello-jni/project/src/com/example/hellojni/HelloJni.java
 */


JNIEXPORT jstring JNICALL
Java_com_example_w_myapplication_MainActivity_stringFromJNI(JNIEnv *env, jobject instance) {


    return (*env)->NewStringUTF(env, "Hello from JNI !");
}

新建Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE    := hello-jni
LOCAL_SRC_FILES := hello-jni.c

include $(BUILD_SHARED_LIBRARY)

在build.gradle中配置
配置好，make project即可生成.so文件在app\build\intermediates\ndk-build\debug\lib中。
增加語句：

externalNativeBuild {
        ndkBuild {
            path file("src\\main\\jni\\Android.mk")
        }
    }

完整的代碼：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.3"
    defaultConfig {
        applicationId "com.example.w.myapplication"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    externalNativeBuild {
        ndkBuild {
            path file("src\\main\\jni\\Android.mk")
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    testCompile 'junit:junit:4.12'
}

在java層調用

public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); System.out.println(stringFromJNI()); } public native String stringFromJNI(); static { System.loadLibrary("hello-jni"); } }

關於Android編程