Android studio ndk Development

Android studio ndk Development
Create a project

Create an android studio project using the wizard

Create a Test class

package cn.edu.zafu.jnidemo;public class Test {    static {        System.loadLibrary("Test");    }    public native String getName();}

Make project

Build-> make project

Generate header files

Open the terminal in as and enter the main directory to generate the header file

cd app/src/mainjavah -d jni -classpath "D:\Program Files\adt-bundle-windows-x64-20140702\sdk\platforms\android-21\android.jar;..\..\build\intermediates\classes\debug" cn.edu.zafu.jnidemo.Test

The directory contains spaces. Please use double quotation marks to include

Then, the header file is generated in the jni directory. copy the file and change it to. c. The implementation content is as follows:

#include 
  
   JNIEXPORT jstring JNICALL Java_cn_edu_zafu_jnidemo_Test_getName(JNIEnv * env, jobject jObj){        jstring str = (*env)->NewStringUTF(env, "HelloWorld from JNI !");        return str;}
  

Create a new util. c In the jni directory (other names are also allowed). The content is blank; otherwise, an error is reported.

Configure the ndk directory

Open local. properties and add the ndk directory.

sdk.dir=D\:\\Program Files\\adt-bundle-windows-x64-20140702\\sdkndk.dir=D\:\\android-ndk-r10b

Configure build. gradle

Open the file and add the ndk configuration in defaultConfig.

defaultConfig {        ndk {            moduleName "Test"        }    }

Add the following configuration

 productFlavors {        x86 {            versionCode Integer.parseInt("6" + defaultConfig.versionCode)            ndk {                abiFilter "x86"            }        }        mips {            versionCode Integer.parseInt("4" + defaultConfig.versionCode)            ndk {                abiFilter "mips"            }        }        armv7 {            versionCode Integer.parseInt("2" + defaultConfig.versionCode)            ndk {                abiFilter "armeabi-v7a"            }        }        arm {            versionCode Integer.parseInt("1" + defaultConfig.versionCode)            ndk {                abiFilters "armeabi", "armeabi-v7a"            }        }        fat    }

Recompile

Call

package cn.edu.zafu.jnidemo;import android.os.Bundle;import android.support.v7.app.ActionBarActivity;import android.widget.Toast;public class MainActivity extends ActionBarActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Test t=new Test();        Toast.makeText(this,t.getName(),Toast.LENGTH_LONG).show();    }}