Communicate with foreground service android

问题

First question here, but I've been around for a while.

What do I have:

I'm building an Android app which plays audio streams and online playlists. Everything is working fine now, but I'm having issues in communicating with my service.

The music is playing in a Service, started with startForeground, so it doesn't gets killed.

I need to communicate from my activity with the service, for getting the track name, image, and a couple of things more.

Whats my issue:

I think I need to start my service with bindService (instead of my current startService) so the activity can talk to it.

However, when I do that, my service gets killed after closing the Activity.

How can I get both? Binding and foreground service?

Thanks!

回答1:

No. bindService will not start a service . It will just bind to the Service with a service connection, so that you will have the instance of the service to access/control it.

As per your requirement I hope you will have the instance of MediaPlayer in service . You can also start the service from Activity and then bind it. If the service is already running onStartCommand() will be called, and you can check if MediaPlayer instance is not null then simply return START_STICKY.

Change you Activity like this..

public class MainActivity extends ActionBarActivity {

    CustomService customService = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // start the service, even if already running no problem.
        startService(new Intent(this, CustomService.class));
        // bind to the service.
        bindService(new Intent(this,
          CustomService.class), mConnection, Context.BIND_AUTO_CREATE);
    }

    private ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            customService = ((CustomService.LocalBinder) iBinder).getInstance();
            // now you have the instance of service.
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            customService = null;
        }
    };

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (customService != null) {
            // Detach the service connection.
            unbindService(mConnection);
        }
    }
}

I have similar application with MediaPlayer service. let me know if this approach doesn't help you.

回答2:

Quoting Android documentation:

A bound service is destroyed once all clients unbind, unless the service was also started

And about the difference between started and bound just take a look to https://developer.android.com/guide/components/services.html

So, you have to create the Service using startService and then bindService, like @Libin does in his/her example. Then, the service will run until you use stopService or stopSelf or until Android decides that it needs resources and kills you.

来源：https://stackoverflow.com/questions/23017767/communicate-with-foreground-service-android

标签

android

service

bind

foreground

aidl