學習筆記之保活技能之前臺服務和雙進程守護

這次是前臺服務和雙進程守護兩種保活方法。

一、前臺服務部分就簡單多了，就是開啓一個前臺服務，然後在這個前臺服務內創建一個內部服務，在做相應Android API 相應的處理。具體代碼如下：

ForegroundService前臺服務裏代碼：

public class ForegroundService extends Service {

    private static final int SERVICE_ID = 1;

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (Build.VERSION.SDK_INT < 18) {
            //4.3
            startForeground(SERVICE_ID, new Notification());
        } else if (Build.VERSION.SDK_INT < 26) {
            //7.0
            startForeground(SERVICE_ID, new Notification());
            //刪除通知欄消息
            startService(new Intent(this, InnerService.class));
        } else {
            //設置channel
            NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
            //越小，通知重要性越低
            NotificationChannel channel = new NotificationChannel("channel", "dd", NotificationManager.IMPORTANCE_MIN);
            if (manager != null) {
                manager.createNotificationChannel(channel);
                Notification notification = new NotificationCompat.Builder(this, "channel").build();

                startForeground(SERVICE_ID, notification);
            }
        }
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onCreate() {
        super.onCreate();
        // 定時打印日誌
        mHandler.postDelayed(r, 100);
    }

    public static class InnerService extends Service {

        @Nullable
        @Override
        public IBinder onBind(Intent intent) {
            return null;
        }

        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            startForeground(SERVICE_ID, new Notification());
            stopForeground(true);
            stopSelf();
            return super.onStartCommand(intent, flags, startId);
        }
    }

    Handler mHandler = new Handler();
    Runnable r = new Runnable() {

        @Override
        public void run() {
            //do something
            //每隔1s循環執行run方法
            KLog.e("我是前臺服務，我還活着..................");
            mHandler.postDelayed(this, 1000);
        }
    };
}

清單內配置：

<service android:name=".service.ForegroundService"/>
<service android:name=".service.ForegroundService$InnerService"/>

最後在MainActivity中開啓前臺服務

//前臺服務
startService(new Intent(this, ForegroundService.class));

二、雙進程守護，就是依靠一個本地服務和遠程服務，相互拉活（相互啓動）來實現始終有一個服務在運行，就算APP不在前臺，也還能夠跟後臺通訊。實現代碼也很簡單，具體如下

本地服務LocalService：

public class LocalService extends ForegroundService {

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        bindService(new Intent(LocalService.this, RemoteService.class), mConnection, Service.BIND_IMPORTANT);
        return super.onStartCommand(intent, flags, startId);
    }

    private ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            //1
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            //2
            startService(new Intent(LocalService.this, RemoteService.class));
            bindService(new Intent(LocalService.this, RemoteService.class), mConnection, Service.BIND_IMPORTANT);
        }
    };
}

遠程服務RemoteService：

public class RemoteService extends ForegroundService {

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        bindService(new Intent(RemoteService.this, LocalService.class), mConnection, Service.BIND_IMPORTANT);
        return super.onStartCommand(intent, flags, startId);
    }

    private ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            //1
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            //2
            startService(new Intent(RemoteService.this, LocalService.class));
            bindService(new Intent(RemoteService.this, LocalService.class), mConnection, Service.BIND_IMPORTANT);
        }
    };

}

然後我們需要在前臺服務ForegroundService中修改下onBind方法中創建一個LocalBinder來返回

@Nullable
    @Override
    public IBinder onBind(Intent intent) {
//        return null; // 前臺服務保活時使用
        return new LocalBinder(); // 雙進程守護時使用
    }

    private class LocalBinder extends Binder {

    }

後面還需要在清單內註冊下這兩個服務

<service android:name=".service.LocalService" />
<service
    android:name=".service.RemoteService"
    android:process=":remote" /> //注意標註

最後我們在MainActivity中啓用這兩個服務就OK了，

//  雙進程守護
startService(new Intent(this, LocalService.class));
startService(new Intent(this, RemoteService.class));

寫文章的不多，有什麼不對的和意見歡迎大家多多指教。