Android中单APK应用多进程
16lz
2021-01-23
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
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> <action android:name = "android.intent.action.MAIN" /> <category android:name = "android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name = ".MyService" android:label = "@string/title_activity_main" > </service> </application> </manifest>文件5 values\strings.xml
<resources> <string name = "app_name" > Test </string> <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：
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> <action android:name = "android.intent.action.MAIN" /> <category android:name = "android.intent.category.LAUNCHER" /> </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。 更多相关文章
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