在没有活动的情况下运行IntentService

Question

我有一个需要在后台永久运行的服务，但是一旦活动关闭，它创建的IntentService也会立即运行：public class CAS extends IntentService {  public CAS() {    super("CAS");  }  Sensor accelerometer;  SensorManager sensorManager;  CA cA= new CA();  @Override  protected void onHandleIntent(@Nullable Intent intent) {    sensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);    accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);    sensorManager.registerListener(cA, accelerometer, SensorManager.SENSOR_DELAY_FASTEST);    LocationManager locationManager = GlobalFunctions.LocationLibrary.getLocationManager(this);    cA.start(this, locationManager);  }}我如何才能使此类在后台无限期地运行，甚至在Android运行时也可以启动？