Question

I create the following fragment in “ActionBarMain.java”

    FragMent1 fram1;

FragmentTransaction fragMentTra = null;

public void onTabSelected(Tab tab, FragmentTransaction ft) {

    if (tab.getText().equals("Collection")) {
        try {
            rl.removeAllViews();
        } catch (Exception e) {
        }
        fram1 = new FragMent1();
        fragMentTra.addToBackStack(null);
        fragMentTra = getFragmentManager().beginTransaction().add(rl.getId(), fram1);
        fragMentTra.commit();

}

//And in here I create a new activity
         Intent intent = new Intent(this, AddBookActivity.class);
         startActivity(intent);

So naturally I should be able to perform the findFragmentByTag(fram1)

Now I am in the “AddBookActivity” and have added a new item to an arraylist that fram1 prints out in a simple_list_item_1 so now I want to refresh fram1, how do I do that in AddBookActivity??

//AddBookActivity.java
@Override
        public boolean onOptionsItemSelected(MenuItem item) {
            switch (item.getItemId()) {
            case R.id.addBook:
                FragmentManager fragmentManager = getFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                Fragment newFragment = new FragMent1();
                FragmentTransaction transaction = getFragmentManager().beginTransaction();
                //How do I find out the fragment id from findFragmentByTag(fram1)????
                transaction.replace(R.id.your_fragment_id, newFragment);//Whats the id, I have the Tag that is fram1
                transaction.addToBackStack(null);
                transaction.commit();
                return true; 
            case R.id.cancel:
                super.finish(); 
                return (true);

            }

            return (super.onOptionsItemSelected(item));
        }

Answer 1

findFragmentByTag takes a String as a parameter, not a Fragment

so you would use

fragMentTra = getFragmentManager().beginTransaction().add(rl.getId(), fram1, "fram1");

to add, and replace using

transaction.replace(R.id.your_fragment_id, newFragment, "fram1");

to find the fragment, use

findFragmentByTag("fram1");

Whether that will update your list is another matter, since the code you posted does not address that.

EDIT:

Your Activity can load multiple Fragments, and therefore the Activity layout will depend on the screen size. Simplest use is that it is only large enough for one Fragment. This Fragment is a FragmentList or it contains a ListView. The list requires an Adapter to bind the data to the list. Simple example is a ArrayAdapter of type String e.g. ArrayAdapter<String>. You assign the ListView to use the ArrayAdapter as its data source. You can then change the ArrayAdapters underlaying data (ArrayList<String> or String[]) directly (requires the adapter to be notified of the change) or via the adapter itself. More complex views can be achieved by extending a adapter class.

I suggest looking at ListView and FragmentList SDK samples.