Android中单APK应用多进程

本人博客原文

Android中，默认一个APK包就对应一个进程，其进程名就为AndroidManifest.xml文件中指定的package名。我们可以通过Activity, Service, BroadCastReceiver, ContentProvider的android:process属性来实现单APK多进程

但是需要注意进程间内存的不可见性。

实例1

文件1 MainActivity.java

package com . lenovo . robin . test ;

import android . os . Bundle ;

import android . app . Activity ;

import android . content . Intent ;

import android . util . Log ;

import android . view . Menu ;

import android . view . MenuItem ;

import android . support . v4 . app . NavUtils ;

public class MainActivity extends Activity {

static boolean iscreated = false ;

final static String TAG = "robin" ;

@Override

public void onCreate ( Bundle savedInstanceState ) {

super . onCreate ( savedInstanceState );

setContentView ( R . layout . activity_main );

iscreated = true ;

Log . i ( TAG , "on create() in MainActivity" );

this . startService ( new Intent ( this , MyService . class ));

}

文件2 MyService.java

package com . lenovo . robin . test ;

import android . app . Service ;

import android . content . Intent ;

import android . os . IBinder ;

import android . util . Log ;

public class MyService extends Service {

String tag = "robin" ;

@Override

public void onCreate () {

Log . i ( tag , "MyService is oncreate" );

}

@Override

public int onStartCommand ( Intent intent , int flags , int startId ) {

Log . i ( tag , "MainActivity is created: " + MainActivity . iscreated );

return START_STICKY ;

}

@Override

public void onDestroy () {

Log . i ( tag , "OnDestory" );

}

@Override

public IBinder onBind ( Intent arg0 ) {

return null ;

}

文件 3 layout\activity_main.xml

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

xmlns:tools = "http://schemas.android.com/tools"

android:layout_width = "match_parent"

android:layout_height = "match_parent" >

<TextView

android:layout_width = "wrap_content"

android:layout_height = "wrap_content"

android:layout_centerHorizontal = "true"

android:layout_centerVertical = "true"

android:text = "@string/hello_world"

tools:context = ".MainActivity" />

</RelativeLayout>

文件4 AndroidManifest.xml

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

package = "com.lenovo.robin.test"

android:versionCode = "1"

android:versionName = "1.0" >

<uses-sdk

android:minSdkVersion = "8"

android:targetSdkVersion = "15" />

<application

android:icon = "@drawable/ic_launcher"

android:label = "@string/app_name"

android:theme = "@style/AppTheme" >

<activity

android:name = ".MainActivity"

android:label = "@string/title_activity_main" >

<intent-filter>

</intent-filter>

</activity>

<service

android:name = ".MyService"

android:label = "@string/title_activity_main" >

</service>

</application>

</manifest>

文件5 values\strings.xml

<string name = "hello_world" > Hello world! </string>

<string name = "menu_settings" > Settings </string>

<string name = "title_activity_main" > MainActivity </string>

</resources>

运行该应用程序

DDMS截图显示的进程如下：

Android中如何实现单APK多进程 - hubingforever - 民主与科学

运行打印出的日志如下：

08-12 21:55:32.365: I/robin(25964): on create() in MainActivity

08-12 21:55:32.435: I/robin(25964): MyService is oncreate

08-12 21:55:32.435: I/robin(25964): MainActivity is created: true

我们对 AndroidManifest.xml文件进行修改，以实现当APK应用多进程。

修改后的 AndroidManifest.xml文件如下

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

package = "com.lenovo.robin.test"

android:versionCode = "1"

android:versionName = "1.0" >

<uses-sdk

android:minSdkVersion = "8"

android:targetSdkVersion = "15" />

<application

android:icon = "@drawable/ic_launcher"

android:label = "@string/app_name"

android:theme = "@style/AppTheme" >

<activity

android:name = ".MainActivity"

android:label = "@string/title_activity_main" >

<intent-filter>

</intent-filter>

</activity>

<service

android:name = ".MyService"

android:label = "@string/title_activity_main"

android:process = "com.lenove.robin.test.service" >

</service>

</application>

</manifest>

DDMS截图显示的进程如下：

运行打印出的日志如下：

08-11 06:58:56.917: I/robin(10561): on create() in MainActivity

08-11 06:58:57.037: I/robin(10572): MyService is oncreate

08-11 06:58:57.037: I/robin(10572): MainActivity is created: false

虽然我们在MainActivity的onCreate中把iscreated变量设置为了true,因为进程间内存的不可见性，，所以才会打印日志“ MainActivity is created: false”。

简单点说就是每个进程都是运行在不同的虚拟机上，对于不同的进程，他们载入的Class文件虽然名字一样（比如都是 com.lenovo.robin.test.MainActivity ），但是他们其实是加载到了不同的内存地址空间。

com.lenovo.robin.test.MainActivity 中把 iscreated 变量设置为true,它其实只是把当前进程（ com.lenovo.robin.test ）的MainActivity类的iscreated变量的设置为了true,

com.lenove.robin.test.service 进程中的 com.lenovo.robin.test.MainActivity 类和它位于不同的内存地址空间，当然其变量iscreated也位于不同的内存地址空间，自然也不受影响。

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Android中单APK应用多进程

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