LocalBroadcastManager doesn't send message from service to activity

Question

I'm trying to connect my service and activity, tried different approaches, but nothing worked for me.

I start Servise in SplashActivity, when the app launches. Then Service do some work in background, and when this work is done, stopself() method is calling in onStartCommand() in Service.

Also there is another activity where should be results from this background work. The problem, that i need to load data into Recyclerview only when work is done and Service is stopped. So I Tried to use LocalBroadcastManager and send message to the activity before stopself() method.

The problem is, activity doesn't get any messages from Service. Here is my code, it's from this answer on stackoverflow - https://stackoverflow.com/a/8875292/7478869

Service:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    helper = ItemDatabaseHelper.getInstance(this);
    preferences = getSharedPreferences(PREFERENCES, MODE_MULTI_PROCESS);
    editor = preferences.edit();
    helper.clearTable(Contacts_Contract.CONTACT_TABLE_NAME);
    Set<ContactItem> setC = getContactList();
    for(ContactItem item: setC){
        helper.insertContacts(item);
    }
    editor.putBoolean(IS_CONTACTS_IMPORTED, true);
    editor.apply();


    Intent intent2 = new Intent("myevent");
    // You can also include some extra data.
    intent2.putExtra("message", "This is my message!");
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent2);

    Log.d(TAG, "onStartCommand: stopping service");
    stopSelf();
    return START_STICKY;
}

Activity:

    @Override
protected void onCreate(Bundle savedInstanceState) {
    Log.d(TAG, "onCreate: starts");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contacts);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    // Register to receive messages.
    // We are registering an observer (mMessageReceiver) to receive Intents
    // with actions named "custom-event-name".
    LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
            new IntentFilter("myevent"));


}

// Our handler for received Intents. This will be called whenever an Intent
// with an action named "custom-event-name" is broadcasted.
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Get extra data included in the Intent
        String message = intent.getStringExtra("message");
        Log.e("receiver", "Got message: " + message);
        Toast.makeText(context, "Import completed", Toast.LENGTH_SHORT).show();
    }
};

Do you have an `android:process` attribute on any of these components in the manifest? And are these all part of one app? — CommonsWare, Sep 19 '17 at 14:28
@CommonsWare yes, this is one app. In manifest, the service has attribute: — Big Coach, Sep 19 '17 at 14:40

score 1 · Answer 1 · answered Sep 19 '17 at 14:42

1

Tactically, the reason why this does not work is that LocalBroadcastManager is local to a process, and you have two processes.

Strategically, having this code in a separate process is unnecessary and dangerous. For example, you are relying on MODE_MULTI_PROCESS, which has been deprecated for over two years and never worked especially well in the first place.

answered Sep 19 '17 at 14:42

CommonsWare

986,068
189
2,389
2,491

how is MODE_MULTI_PROCESS in sharedpreferences connected with my problem with LocalBroadcastManager? – Big Coach Sep 19 '17 at 14:46
@BigCoach: You decided to implement a service (I do not know why) and have that service be in a separate process (I do not know why). Having the service be in a separate process is why `LocalBroadcastManager` is not working. My second paragraph is simply there to try to convince you that you should not be using a service in a separate process here. – CommonsWare Sep 19 '17 at 14:49

LocalBroadcastManager doesn't send message from service to activity

1 Answers1