三、不同进程之间的service交互

此次记录一下不同进程之间的service使用Messenger进行交互，未使用AIDL。     1、在AndroidManifest.xml文件中注册service <service android:name=".RemoteMessageService.MessageService" android:enabled="true"//表示可以将service实例化 android:exported="true"//表示可以在不同的进程中连接service //":remote"表示在新建一个属于当前应用的进程，名为“remote”,这样可以实现不同进程的通信 android:process=":remote"> <intent-filter> <action android:name="msg"/> <category android:name="android.intent.category.DEFAULT"/> </intent-filter> </service>     2、继承Service public class MessageService extends Service{ private ArrayList<Messenger> messengers=new ArrayList<Messenger>();//存储客户端的Messenger private String value; private final int REGISTER =1; private final int UNREGISTER =2; private final int VALUE = 3; private Messenger messenger=new Messenger(new IncomingHandler()); class IncomingHandler extends Handler{ @Override public void handleMessage(Message msg) { switch ( msg.what){ case REGISTER: messengers.add(msg.replyTo); break; case UNREGISTER: messengers.remove(msg.replyTo); break; case VALUE: for(int i=0;i<=messengers.size()-1;i++){ try { Log.i("LZH","get value"); //处理完数据后，将结果返回给客户端，此时要注意send方法中的Object参数，这个参数在此时不能是基本类型（int，String等），需要是实现Parcelable的实例，或是Bundle实例 messengers.get(i).send(Message.obtain(null,VALUE,msg.obj));//实际上给了客户端的Handler去处理 } catch (RemoteException e) { e.printStackTrace(); } } break; } } } @Nullable @Override public IBinder onBind(Intent intent) { return messenger.getBinder(); } @Override public void onDestroy() { Log.i("LZH","messsege service destroy"); super.onDestroy(); } } 3、实现Activity public class RemoteActivity extends Activity{ private Messenger messenger; private Messenger remessg; private final int REGISTER =1; private final int UNREGISTER =2; private final int VALUE = 3; private String str; private MyServiceConnection connection; private Intent intent; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.remote_layout); connection=new MyServiceConnection(); intent=new Intent("msg"); intent.setPackage("com.example.administrator.myservice.RemoteMessageService"); } public void remote_bind(View view){ bindService(intent,connection,BIND_AUTO_CREATE); } public void remote_unbind(View view){ if(connection!=null&&status==true){ status=false; Message message=Message.obtain(null,UNREGISTER,null); message.replyTo=remessg; try { messenger.send(message); } catch (RemoteException e) { e.printStackTrace(); } unbindService(connection); } } class MyHandler extends Handler{ @Override public void handleMessage(Message msg) { switch(msg.what){ case VALUE: Bundle bundle= (Bundle) msg.obj; str=bundle.getString("key"); Log.i("LZH","str is "+str); break; } } } class MyServiceConnection implements ServiceConnection{ private MessageService.IncomingHandler mincomingHandler; @Override public void onServiceConnected(ComponentName name, IBinder service) { messenger=new Messenger(service); remessg=new Messenger(new MyHandler()); Message message=Message.obtain(null,REGISTER,null); message.replyTo=remessg; try { //先在服务端注册，即将客户端的Messenger传送到服务端的list中 messenger.send(message); } catch (RemoteException e) { e.printStackTrace(); } //向服务端发送信息 try { Bundle bundle=new Bundle(); bundle.putString("key","hi"); message=Message.obtain(null,VALUE,bundle); messenger.send(message); } catch (RemoteException e) { e.printStackTrace(); } } @Override public void onServiceDisconnected(ComponentName name) { } } @Override protected void onDestroy() { if(connection!=null&&status==true){ status=false; Message message=Message.obtain(null,UNREGISTER,null); message.replyTo=remessg; try { messenger.send(message); } catch (RemoteException e) { e.printStackTrace(); } unbindService(connection); } super.onDestroy(); } 总结：     1、首先给Messenger传入一个handler用于处理传来的数据     2、在客户端拿到一个可以连接到服务端的Messenger实例，在服务端拿到一个客户端的Messenger实例     3、在服务连接成功时， 利用Messenger的send方法将数据发送到服务端，然后服务daunt在用相同的方法将结果返回到客户端 处理流程为： Messenger处理过程：