alertdialog 使用系统选择时改变 默认字体大小

ContextThemeWrapper ctw = new ContextThemeWrapper( getActivity(), R.style.AlertDialogCustom );
		Builder builder = new AlertDialog.Builder(btw);

  <style name="AlertDialogCustom" parent="@android:style/Theme.Dialog">
        <item name="android:textSize">15sp</item>
    </style>