Send data from Activity to Fragment already created

Question

I only have found information about how to create a Fragment sending some data to it, but only in its instantiation with the constructor.

But I want to know if it is

Answer 1

The easiest way to do this is to define an interface in the Fragment and implement it within the activity. This link should provide a detailed example on how this can be accomplished. https://developer.android.com/training/basics/fragments/communicating.html

I think the key part you are looking for is here:

ArticleFragment articleFrag = (ArticleFragment)
      getSupportFragmentManager().findFragmentById(R.id.article_fragment);

if (articleFrag != null) {
    // If article frag is available, we're in two-pane layout...

    // Call a method in the ArticleFragment to update its content
    articleFrag.updateArticleView(position);
} else {
    // Otherwise, we're in the one-pane layout and must swap frags...

    // Create fragment and give it an argument for the selected article
    ArticleFragment newFragment = new ArticleFragment();
    Bundle args = new Bundle();
    args.putInt(ArticleFragment.ARG_POSITION, position);
    newFragment.setArguments(args);

    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

    // Replace whatever is in the fragment_container view with this fragment,
    // and add the transaction to the back stack so the user can navigate back
    transaction.replace(R.id.fragment_container, newFragment);
    transaction.addToBackStack(null);

    // Commit the transaction
    transaction.commit();
}

First try to retrieve the fragment by calling findFragmentById(R.id.fragment_id), and if it is not null you can make a call to the method you defined in your interface to send some data to it.