【移動(dòng)應(yīng)用開發(fā)技術(shù)】Android Jni代碼的示例分析

【移動(dòng)應(yīng)用開發(fā)技術(shù)】AndroidJni代碼的示例分析

AndroidJni使用方法步驟(1)Eclipse中新建Android工程AndroidJni使用方法步驟(2)編輯main.xml<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

xmlns:android="http://schemas.A/apk/res/Android"

Android:orientation="vertical"

Android:layout_width="fill_parent"

Android:layout_height="fill_parent"

>

<TextView

Android:id="@+id/JNITest"

Android:layout_width="fill_parent"

Android:layout_height="wrap_content"

Android:text="@string/JNITest"

/>

</LinearLayout>

<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

xmlns:android="http://schemas.A/apk/res/Android"

Android:orientation="vertical"

Android:layout_width="fill_parent"

Android:layout_height="fill_parent"

>

<TextView

Android:id="@+id/JNITest"

Android:layout_width="fill_parent"

Android:layout_height="wrap_content"

Android:text="@string/JNITest"

/>

</LinearLayout>

AndroidJni使用方法步驟(3)編輯java文件package

com.ura.test;

import

Android.app.Activity;

import

Android.os.Bundle;

import

Android.widget.TextView;

public

class

JNITest

extends

Activity

{

/**

Called

when

the

activity

is

first

created.

*/

static

{

System.loadLibrary("JNITest");

}

public

native

String

GetTest();

@Override

public

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

String

str

=GetTest();

TextView

JNITest

=

(TextView)findViewById(R.id.JNITest);

JNITest.setText(str);

}

}javah

-classpath

bin

-d

jni

com.ura.test.JNItest/*

DO

NOT

EDIT

THIS

FILE

-

it

is

machine

generated

*/

#include

<

jni.h>

/*

Header

for

class

com_ura_test_JNITest

*/

#ifndef

_Included_com_ura_test_JNITest

#define

_Included_com_ura_test_JNITest

#ifdef

__cplusplus

extern

"C"

{

#endif

/*

*

Class:

com_ura_test_JNITest

*

Method:

GetTest

*

Signature:

()Ljava/lang/String;

*/

JNIEXPORT

jstring

JNICALL

Java_com_ura_test_JNITest_GetTest

(JNIEnv

*,

jobject);

#ifdef

__cplusplus

}

#endif

#endifAndroidJni使用方法步驟(5)編寫c/c++文件如下#include

"com_ura_test_JNITest.h"

#define

LOG_TAG

"JNITest"

#undef

LOG

#include

<

utils/Log.h>

JNIEXPORT

jstring

JNICALL

Java_com_ura_test_JNITest_GetTest

(JNIEnv

*

env,

jobject

obj)

{

return

(*env)->NewStringUTF(env,

(char

*)"JNITest

Native

String");

LOGD("Hello

LIB!\n");

}

#include

"com_ura_test_JNITest.h"

#define

LOG_TAG

"JNITest"

#undef

LOG

#include

<

utils/Log.h>

JNIEXPORT

jstring

JNICALL

Java_com_ura_test_JNITest_GetTest

(JNIEnv

*

env,

jobject

obj)

{

return

(*env)->NewStringUTF(env,

(char

*)"JNITest

Native

String");

LOGD("Hello

LIB!\n");

}

AndroidJni使用方法步驟(6)編寫Android.mk文件LOCAL_PATH:=

$(call

my-dir)

include

$(CLEAR_VARS)

LOCAL_SRC_FILES:=

\

com_ura_test_JNITest.c

LOCAL_C_INCLUDES

:=

\

$(JNI_H_INCLUDE)

LOCAL_SHARED_LIBRARIES

:=

libutils

LOCAL_PRELINK_MODULE

:=

false

LOCAL_MODULE

:=

libJNITest

include

$(BUILD_SHARED_LIBRARY)AndroidJni使用方法步驟(7)編譯生成動(dòng)態(tài)庫(kù)~/mydroid/external/libJNITestcd

cd

mydroid/build/

envsetup.sh

cd

~/mydroid

cd

external/libJNITest/