Android : Foor loop adds only one item

I want to add a LinearLayout for every item in my draw folder. This is my Code:

    final float scale = MlgMainActivity.this.getResources().getDisplayMetrics().density;
    LinearLayout ll = (LinearLayout)findViewById(R.id.ll);
    Field[] sounds = R.raw.class.getFields();
    for(int i = 0; i < sounds.length; i++) {
        LinearLayout layoutVertical = new LinearLayout(this);
        layoutVertical.setOrientation(LinearLayout.VERTICAL);
        layoutVertical.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, (int) (60 * scale + 0.5f)));
        layoutVertical.setBackgroundColor((Color.parseColor("#000000")));
        ll.addView(layoutVertical);

        LinearLayout layoutHorizontal1 = new LinearLayout(this);
        layoutHorizontal1.setOrientation(LinearLayout.HORIZONTAL);
        layoutHorizontal1.setLayoutParams(new LinearLayout.LayoutParams((int)(MlgMainActivity.this.getResources().getDisplayMetrics().widthPixels * 0.65), LinearLayout.LayoutParams.FILL_PARENT));
        layoutHorizontal1.setBackgroundColor((Color.parseColor("#ffffff")));
        layoutVertical.addView(layoutHorizontal1);


        TextView test = new TextView(this);
        test.setText(String.valueOf(sounds[i].getName()));
        test.setTextAppearance(this, R.style.TextAppearance_AppCompat_Large);
        layoutHorizontal1.addView(test);


    }

sounds.length is 4 but it only shows the first item and only adds one LinearLayout.

Maybe someone here has an idea?