Android Studio 2.1.2 Ndk開發步驟

必要修改1：
build.gradle文件：
// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle-experimental:0.7.0'    //修改了

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

必要修改2：
app\build.gradle文件：
apply plugin: 'com.android.model.application'        //修改了

model{                                                //修改了
    android {
        compileSdkVersion 22
        buildToolsVersion "24"

        defaultConfig {
            applicationId "myself.exercise.myndktest"
            minSdkVersion.apiLevel 15                //修改了
            targetSdkVersion.apiLevel 22//修改了
            versionCode 1
            versionName "1.0"
        }
        buildTypes {
            release {
                minifyEnabled false
                //proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
                proguardFiles.add(file("proguard-rules.pro"))   //修改了
            }
        }
        ndk{
            moduleName "lb"                        //增加的部分
        }
    }
}
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile 'com.android.support:design:22.2.1'
}
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方法一：
步驟1：
右鍵app->src->main: New->Folder->JNI Folder 不用勾選CheckBox

步驟2：
右鍵app->src->main->java->myself.exercise.myndktestt: New->Java Class->填寫Class名稱，這裏爲Load
內容爲
public class Load {
    static {
        System.loadLibrary("lb");
    }
    public native String getCLanguageString();
}

步驟3：
Build->Make Project

步驟4：
cd app\build\intermediates\classes\debug
javah -jni myself.exercise.myndktestt.Load    //這裏Load第一個字母爲大寫
發現app\build\intermediates\classes\debug目錄下多出一個myself_exercise_myndktestt_Load.h

步驟5：
將myself_exercise_myndktestt_Load.h剪貼到app\src\main\jni目錄下

在該jni目錄右鍵 New->C/C++ Source File, 名稱隨意起.

如果爲cpp, 內容爲：
#include "myself_exercise_myndktestt_Load.h"
JNIEXPORT jstring JNICALL Java_myself_exercise_myndktestt_Load_getCLanguageString
  (JNIEnv * env, jobject)
{
    return env->NewStringUTF("This just a test for Android Studio NDK JNI developer!");
}
如果爲c, 內容爲：
#include "myself_exercise_myndktestt_Load.h"
JNIEXPORT jstring JNICALL Java_myself_exercise_myndktestt_Load_getCLanguageString
  (JNIEnv * env, jobject)
{
    return (*env)->NewStringUTF(env, "This just a test for Android Studio NDK JNI developer!");
}

步驟6：
在MainActivity.java中加入調用
Load ld = new Load();
Toast.makeText(getApplicationContext(), ld.getCLanguageString(), Toast.LENGTH_SHORT).show();