How to get a String List from Firebase to fill a Spinner

Question

my database is arranged like this:

I want to get all the values from areaName as a String List or any form of list and use it to populate a

Answer 1

I didn't test that code but, more or less, that is what you have to do:

fDatabaseRoot.child("areas").addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        // Is better to use a List, because you don't know the size 
        // of the iterator returned by dataSnapshot.getChildren() to
        // initialize the array
        final List<String> areas = new ArrayList<String>();

        for (DataSnapshot areaSnapshot: dataSnapshot.getChildren()) {
            String areaName = areaSnapshot.child("areaName").getValue(String.class);
            areas.add(areaName);
        }

        Spinner areaSpinner = (Spinner) findViewById(R.id.spinner);
        ArrayAdapter<String> areasAdapter = new ArrayAdapter<String>(UAdminActivity.this, android.R.layout.simple_spinner_item, areas);
        areasAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        areaSpinner.setAdapter(areasAdapter);
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

I hope it's helps!

Regards.