如何设置对话框按钮文本的字体大小

而不是返回

builder.create()

final alertDialog alert = builder.create();alert.setonShowListener(new DialogInterface.onShowListener() {    @Override    public void onShow(DialogInterface dialog) {        Button btnPositive = alert.getButton(Dialog.BUTTON_POSITIVE);        btnPositive.setTextSize(TEXT_SIZE);        Button btnNegative = alert.getButton(Dialog.BUTTON_NEGATIVE);        btnNegative.setTextSize(TEXT_SIZE);    }});return alert;