Question

I created a Handler in my activity. The handler will be stored in the application object.

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.action_activity);
    appData = (AttachApplication) getApplication();

    Handler updateHandler = new Handler() {
        public void handlerMessage(Message msg) {
            Log.d( TAG, "handle message " );
        }
    };
    appData.setUpdateHandler( updateHandler );


}

My plan is that this handleMessage will be called when i setEmtpyMessage in my service. The service retrieves the handler from the application object.

public int onStartCommand(Intent intent, int flags, int startId) {
    Log.d(TAG, "onStartCommand of attachService");
    List<Job> jobList = DBManager.getInstance().getAllOpenJobs();
    appData = (AttachApplication) getApplication();
    updateHandler = appData.getUpdateHandler();
            updateHandler.sendEmptyMessage( 101 );

I checked the logs, but there is no handle message so that it seems that my plan does not work. I want to update a textfield each time my service did its job.

Answer 1

In Your case You shoild use BroadcastReceiver like this:

define receiver in your Activity class:

public class DataUpdateReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(MainService.REFRESH_DATA_INTENT)) {
                        //do something
        }
    }
}

on your onCreate or onStart method you must register receiver:

DataUpdateReceiver dataUpdateReceiver = new DataUpdateReceiver();
IntentFilter intentFilter = new IntentFilter(MainService.REFRESH_DATA_INTENT);
registerReceiver(dataUpdateReceiver, intentFilter);

on your service add this:

public static final String REFRESH_DATA_INTENT = "done";

and when you done all staff you must send brocast like this:

sendBroadcast(new Intent(MainService.REFRESH_DATA_INTENT));