How to set font custom font to Spinner text programmatically?

This is what worked for me (using ideas both from CommonsWare’s and gsanllorente’s answers):

private static class MySpinnerAdapter extends ArrayAdapter<String> {
    // Initialise custom font, for example:
    Typeface font = Typeface.createFromAsset(getContext().getAssets(),
                        "fonts/Blambot.otf");

    // (In reality I used a manager which caches the Typeface objects)
    // Typeface font = FontManager.getInstance().getFont(getContext(), BLAMBOT);

    private MySpinnerAdapter(Context context, int resource, List<String> items) {
        super(context, resource, items);
    }

    // Affects default (closed) state of the spinner
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView view = (TextView) super.getView(position, convertView, parent);
        view.setTypeface(font);
        return view;
    }

    // Affects opened state of the spinner
    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        TextView view = (TextView) super.getDropDownView(position, convertView, parent);
        view.setTypeface(font);
        return view;
    }
}

If you, like me, originally populated the Spinner using ArrayAdapter.createFromResource() and an array resource (as in Spinner documentation), then you’d use MySpinnerAdapter like this:

MySpinnerAdapter<String> adapter = new MySpinnerAdapter(
        getContext(),
        R.layout.view_spinner_item,
        Arrays.asList(getResources().getStringArray(R.array.my_array))
);
spinner.setAdapter(adapter);