BroadcastReceiver to send notification and update

问题:

I have an activity which just displays a daily counter. When the day ends, i want to send a notification with last day counter, insert it in a db and if the app is running update the counters label to zero.

I think i must register a static <receiver>android.intent.action.DATE_CHANGED</receiver>. so as to get notified even if the activity is not running. There I insert the value in DB and i send the notification.

And a dynamic created broadcast receiver which i will unregister onPause, which receives the same events, but it will only update the UI and specifically the label.

Is this the best solution?

Is there any way from a broadcastReceiver to make my Activity (if is running) to go to resume again ? Is it possible from broadcastReceiver to call a Service, which will update my UI if my Activity is running?

回答1:

Use broadcastreceiver that would catch the event

public class EventReceiver extends WakefulBroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        ComponentName comp = new ComponentName(context.getPackageName(),
                NotificationService.class.getName());
        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
    }
}

broadcastreceiver give event service

public class NotificationService extends IntentService {

    private final ServiceBinder binder = new ServiceBinder();
    private ServiceListener serviceListener;

    public NotificationService() {
        super("NotificationService");
    }
    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    @Override
    public boolean onUnbind(Intent intent) {
        serviceListener = null;
        return true;
    }

    @Override
    public void onRebind(Intent intent) {
        super.onRebind(intent);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        //send notification
        if(serviceListener != null){
            serviceListener.updateActivity();
        }
    }

    public void setServiceListener(ServiceListener serviceListener) {
        this.serviceListener = serviceListener;
    }

    public class ServiceBinder extends Binder {
        public NotificationService getSevice(){
            return NotificationService.this;
        }
    }

    public static interface ServiceListener{
        public void updateActivity();
    }
}

then you need to connect to the service in your activity

public class MainActivity extends Activity implements NotificationService.ServiceListener {
    private boolean isBound;
    private ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            NotificationService.ServiceBinder binder = ((NotificationService.ServiceBinder)service);
            binder.getSevice().setServiceListener(MainActivity.this);
            isBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    @Override
    protected void onResume() {
        super.onResume();
        if(!isBound) {
            Intent intent = new Intent(this, NotificationService.class);
            bindService(intent, serviceConnection, BIND_AUTO_CREATE);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if(isBound){
          unbindService(serviceConnection);
          isBound = false;
        }
    }

    @Override
    public void updateActivity() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                //update you list here
            }
        });
    }
}

and do not forget to mention the service and broadcastreceiver in the manifest file and specify the intent filter

<receiver android:name="EventReceiver">
    <intent-filter>
       <action android:name="........." /> 
    </intent-filter>
</receiver>
<service android:name="NotificationService"/>

回答2:

You can simply use a LocalBroadcastReceiver to send events to your Activity , a working example could be found here

回答3:

After more reading i found that the best solution is the above.

A static broadcast receiver for DATE_CHANGED actions. This will start a Service which will update the db and send a local custom broadcast (com.myBroadcast.WakeUpActivity) The Activity if is running will register a receiver for the previous custom broadcast (will unregister onPause), and will update the UI.