How can my service change values of variables and UI textfields of my activities?

Question

I have an application that get/send data from/to a remote DB on internet.

I need to get my application working in background mode, then i supose that i have to put all the send/get remote data in a service.....

but.... How can this service change values of variables and UI textfields of my activities?

i can't find any information about this, all the tutorials i am finding are of simple services that doesn't do something like that

can someone explain me how to do it please?

Answer 1

Use a BroadcastReceiver

In your Activity place the following code:

private BroadcastReceiver onBroadcast = new BroadcastReceiver() {
    @Override
    public void onReceive(Context ctxt, Intent i) {
        // do stuff to the UI
    }
};

Register the receiver in your onResume():

registerReceiver(onBroadcast, new IntentFilter("mymessage"));

Be sure to unregister in onPause():

unregisterReceiver(onBroadcast);

In your Service, you can post the message to the Application, which will be heard by your Activity:

getApplicationContext().sendBroadcast(new Intent("mymessage"));

If you need to, you can add data to the Intent's bundle to pass to your Activity as well.