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標題: 在Android運行NDK 的Sample [打印本頁]

作者: woff 時間: 2014-10-21 23:53
標題: 在Android運行NDK 的Sample
在Android運行NDK

(在此不解釋如何安裝NDK)

運行平台:Archlinux 64

1.建立Android  專案檔

$android create project -p ./ -t 3 -k net.aminzai.myjni -a MyJniActivity

2.編輯MyJniActivity

package net.aminzai.myjni;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class MyJniActivity extends Activity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
      super.onCreate(savedInstanceState);
      TextView tv = new TextView(this);
      tv.setText(getString());
      setContentView(tv);
}

public native String getString();

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

3.編譯java file

$ant compile

4.產生所需要的c  header

$cd bin/classes

$javah -jni net.aminzai.myjni.MyJniActivity

$cd (Project-Root)

5.建立Android的jni 資料夾

$mkdir jni

6.將header file 移至 jni資料夾底下

$mv bin/classes/net_aminzai_myjni_MyJniActivity.h jni

會看到裏面的內容是

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

#ifndef _Included_net_aminzai_myjni_MyJniActivity
#define _Included_net_aminzai_myjni_MyJniActivity
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class:    net_aminzai_myjni_MyJniActivity
* Method: getString
* Signature: ()Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL Java_net_aminzai_myjni_MyJniActivity_getString
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

7.建立 c file

$vi jni/net_aminzai_myjni_MyJniActivity.c

#include"net_aminzai_myjni_MyJniActivity.h"
/*
* Class:    net_aminzai_myjni_MyJniActivity
* Method: getString
* Signature: ()Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL Java_net_aminzai_myjni_MyJniActivity_getString
  (JNIEnv * env, jobject x){
   return (*env)->NewStringUTF(env, "Complex string calculated in native code");
  }

8.產生編譯用的makefile

$vi (Project_Root)/Application.mk

APP_PROJECT_PATH:=$(call my-dir)
APP_MODULE :=  net_aminzai_myjni_MyJniActivity

$vi (Project_Root)/jni/Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := net_aminzai_myjni_MyJniActivity
LOCAL_SRC_FILES := net_aminzai_myjni_MyJniActivity.c

include $(BUILD_SHARED_LIBRARY)

9.編譯 c file

$ndk-build
Compile thumb  : net_aminzai_myjni_MyJniActivity <= net_aminzai_myjni_MyJniActivity.c
SharedLibrary  : libnet_aminzai_myjni_MyJniActivity.so
Install       : libnet_aminzai_myjni_MyJniActivity.so => libs/armeabi/libnet_aminzai_myjni_MyJniActivity.so

10.編譯&安裝apk

$ant install

11.運行

作者: 花茶喝菊 時間: 2014-11-6 13:03

真的这么神奇？

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