Android 5.0+中的服务

Question

I intended to work like this: user switches on a feature: let say weather. now weather data will come from server every 6 hours and will be shown to widget(remoteview), Now user switches off the feature. then widget should not show the weather or even refresh the data every 6 hours. there are also 3-4 more features like that. Now i had created a service to get all required data and than i have passed them to remoteview. For starting service i had used this in TimeOut Activity:

i = new Intent(TimeOut.this, TimeService.class);
i.setAction("com.example.Weather.Idle");
startService(i);

same for stopping service in switch off code:

stopService(i)

This code was working fine in API <=19. But in Lollipop it crashes at starting or stoping service. I searched a lot in SO and also tried code for Binding or unbinding service but didn't help any. Please help me with some code rather than just links... Thanks in advance :)

Answer 1

Starting a service from any activity class

    Intent intent = new Intent(MainActivity.this, BackgroundService.class);
            startService(intent);

Here is service class code

   public class BackgroundService extends Service{
   public static Context appContext = null;
   @Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}
   @Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // TODO Auto-generated method stub

    if (appContext == null) {
         appContext = getBaseContext();
        }
    Toast.makeText(appContext, "Services Started", Toast.LENGTH_SHORT).show();

    return START_STICKY;
}

Add your logic here. You can do some work here using a thread. You can stop service whenever you want and i hope you will not find any crash.

Answer 2

I have faced similar issue with Service in 5.0. This is probably not the correct answer, but it works. You could try. I use EventBus to communicate with my services. So when I want to stop the service I'd send,

EventBus.getDefault().post(new ServiceEvent(ServiceEvent.STOP_SERVICE));

In the service,

public void onEvent(ServiceEvent event) {
     if (event.getEvent() == ServiceEvent.STOP_SERVICE) {
         methodToStopService();
     }
}

private void methodToStopService() {
   // do some stuff
   stopSelf();
}

Make sure you register your service for events.

private void registerEventBus() {
    EventBus eventBus = EventBus.getDefault();
    if (!eventBus.isRegistered(this)) {
        eventBus.register(this);
    }
}

ServiceEvent class - It's my own class which I use with EventBus.

public class ServiceEvent {
    private int event;
    public static final int STOP_SERVICE = -1;

    public ServiceEvent(int event) {
        this.event  = event;
    }

    public int getEvent() {
        return event;
    }
}