如何一直后台运行，可靠，安卓9 ，p30 亲测

1 ： 使用前台进程是必须的

 Intent intent = new Intent(MainActivity.this, MyService.class);
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                        startForegroundService(intent);
                    } else {
                        startService(intent);
                    }

2 : 在service 里面发送前台可见通知

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

        Log.i(TAG, "onStartCommand: -----");
        if (mBuilder == null) {
            mBuilder = new NotificationCompat.Builder(this,"10");

            NotificationManager notificationManager = (NotificationManager) getSystemService
                    (NOTIFICATION_SERVICE);

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel channel = new NotificationChannel("10", "senblo", NotificationManager.IMPORTANCE_DEFAULT);
//                mBuilder.setChannelId("10");
                notificationManager.createNotificationChannel(channel);
            }

            mBuilder.setLargeIcon(BitmapFactory.decodeResource(BaseApplication.getApplication().getResources(), R.mipmap.ic_launcher_app));
            mBuilder.setSmallIcon(R.mipmap.ic_launcher_app);
            mBuilder.setContentText("senblo sport running");
            mBuilder.setContentTitle("senblo sport");
            mBuilder.setOnlyAlertOnce(true);

            Intent newIntent = new Intent(this, MainActivity.class);
                newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
            mBuilder.setContentIntent(PendingIntent.getActivity(this, 10, newIntent, PendingIntent.FLAG_UPDATE_CURRENT));

            mBuilder.build().flags |= Notification.FLAG_ONGOING_EVENT;
            mBuilder.build().flags |= Notification.FLAG_NO_CLEAR;
        }

        startForeground(10, mBuilder.build());


        return START_STICKY;

    }

3 ：  最最最重要的是，循环发送通知

  @SuppressLint("HandlerLeak")
    private Handler mHandler=new Handler(){

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

            if(mBuilder!=null){
                Log.i(TAG, "handleMessage: -------2");
                startForeground(10, mBuilder.build());
            }
            sendEmptyMessageDelayed(0,3*60*1000);
        }
    };

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


    @Override
    public void onCreate() {
        super.onCreate();
        Log.i(TAG, "onCreate: --------");

        mHandler.sendEmptyMessageDelayed(0,5000);
    }

欧耶 \(^o^)/