AS运用NDK编译及调用

环境

android studio 2.0

安装

File>Other Settings>Default Project Structure…

注意，这里有可能你会发现你的路经不能点击，那是因为被墙了，破墙下载

配置

build.gradle

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle-experimental:0.4.0'

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

allprojects {
    repositories {
        jcenter()
    }
}

app/build.gradle

注意自己写时，要添加=、.apiLevel，写法不一样

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.2"

        defaultConfig.with {
            applicationId = "com.xuie.jnidemo"
            minSdkVersion.apiLevel = 15
            targetSdkVersion.apiLevel = 23
            versionCode = 1
            versionName = "1.0"
        }
    }

    compileOptions.with {
        sourceCompatibility=JavaVersion.VERSION_1_7
        targetCompatibility=JavaVersion.VERSION_1_7
    }

    /*
     * native build settings
     */
    android.ndk {
        moduleName = "hello-jni"
        /*
         * Other ndk flags configurable here are
         * cppFlags.add("-fno-rtti")
         * cppFlags.add("-fno-exceptions")
         * ldLibs.addAll(["android", "log"])
         * stl       = "system"
         */
    }
    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles.add(file('proguard-rules.txt'))
        }
    }
    android.productFlavors {
        // for detailed abiFilter descriptions, refer to "Supported ABIs" @
        // https://developer.android.com/ndk/guides/abis.html#sa
        create("arm") {
            ndk.abiFilters.add("armeabi")
        }
        create("arm7") {
            ndk.abiFilters.add("armeabi-v7a")
        }
        create("arm8") {
            ndk.abiFilters.add("arm64-v8a")
        }
        create("x86") {
            ndk.abiFilters.add("x86")
        }
        create("x86-64") {
            ndk.abiFilters.add("x86_64")
        }
        create("mips") {
            ndk.abiFilters.add("mips")
        }
        create("mips-64") {
            ndk.abiFilters.add("mips64")
        }
        // To include all cpu architectures, leaves abiFilters empty
        create("all")
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.1'
}

编译

新建JniInterface.java
这里直接写出函数添加了native关键字，用补全，就会在hello-jni.c里自动生成函数名称，比以前用javah有质有飞跃。。。
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public class JniInterface {

public native String stringFromJNI();

static {
System.loadLibrary("hello-jni");
}
}
自身调用

1 2	JniInterface jniInterface = new JniInterface(); ((TextView)findViewById(R.id.tv)).setText(jniInterface.stringFromJNI());

他人调用
我们本身NDK调用，是不希望自己的工程里出现C/C++，那就直接可以调用.so，我以armeabi-v7a架构为例进行调用（因为我手机是这个架构），拷贝目录build/intermediates/binaries/debug/all/lib/armeabi-v7a/下的libhello-jni.so到所用工程main/jniLibs/armeabi-v7a下，调用时java目录下同样需要添加JniInterface.java，注意包名要根原来一模一样，然后再调用，实际项目中要将所有架构下的.so都拷贝进去
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JniInterface jniInterface = new JniInterface();
((TextView)findViewById(R.id.tv)).setText("[Use]" + jniInterface.stringFromJNI());