Sending a simple message from Service to Activity

Question

I am trying to find a way to send an integer value from my Service to my MainActivity, yet I can\'t figure it out with the tutorials on the internet. I am using a Handler to rec

Answer 1

Assuming that your Activity and Service are in the same package...

Service side

// Supposing that your value is an integer declared somewhere as: int myInteger;
private void sendMessage() {
  // The string "my-message" will be used to filer the intent
  Intent intent = new Intent("my-message");
  // Adding some data
  intent.putExtra("my-integer", myInteger);
  LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

Activity side

@Override
public void onResume() {
  super.onResume();
  // This registers messageReceiver to receive messages.
  LocalBroadcastManager.getInstance(this)
                       .registerReceiver(messageReceiver, new IntentFilter("my-message"));
}

// Handling the received Intents for the "my-integer" event 
private BroadcastReceiver messageReceiver = new BroadcastReceiver() {
  @Override
  public void onReceive(Context context, Intent intent) {
    // Extract data included in the Intent
    int yourInteger = intent.getIntExtra("my-integer", -1); // -1 is going to be used as the default value
  }
};
    
@Override
protected void onPause() {
  // Unregister since the activity is not visible
  LocalBroadcastManager.getInstance(this).unregisterReceiver(messageReceiver);
  super.onPause();
}