JNI应用程序开发实例1

文件1：

com\teleca\robin\HelloActivity.java

package com.teleca.robin;

import android.app.Activity;

import android.os.Bundle;

import android.widget.TextView;

import com.teleca.robin.R;;

public class HelloActivity extends Activity {

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

TextView textView=(TextView)findViewById(R.id.textView1);

textView.setText(getStringFromJni());

}

native String getStringFromJni();

/* this is used to load the 'hello-jni' library on application

* startup. The library has already been unpacked into

* /data/data/com.example.HelloJni/lib/libhello-jni.so at

* installation time by the package manager.

*/

static {

System.loadLibrary("hello-jni");

}

}

文件2：

jni\hello-jni.c

*/

#include <string.h>

#include<jni.h>

/* 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

*/

jstring

Java_com_teleca_robin_hellojni_HelloActivity_getStringFromJni( JNIEnv* env,

jobject thiz )

{

return (*env)->NewStringUTF(env, "Hello robin,this world is from JNI !");

}

注意：该jni文件要为于jni目录下。

文件3：

jni\Android.mk

# 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.

#

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := hello-jni

LOCAL_SRC_FILES := hello-jni.c

include $(BUILD_SHARED_LIBRARY)

注意1：LOCAL_MODULE是你要生成的so档案文件名。

注意2：LOCAL_SRC_FILES为你要编译的jni代码文件，文件之间用分号";"隔开。

文件4：

res\values\strings.xml

<?xml version="1.0" encoding="utf-8"?>

<resources>

<string name="hello">Hello World, HelloActivity!</string>

<string name="app_name">JiniHello</string>

</resources>

文件5：

res\layout\main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView

android:id="@+id/textView0"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

<TextView

android:id="@+id/textView1"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

</LinearLayout>

文件6：

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.teleca.robin"

android:versionCode="1"

android:versionName="1.0">

<application android:icon="@drawable/icon" android:label="@string/app_name">

<activity android:name=".HelloActivity"

android:label="@string/app_name">

<intent-filter>

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

<uses-sdk android:minSdkVersion="7" />

</manifest>