如何在textview 中指定某段文本为另外字体

TextView view1 = (TextView) this.getView().findViewById(R.id.earn_coins_second_tips);

        SpannableStringBuilder style = new SpannableStringBuilder(view1.getText());

        style.setSpan(new StyleSpan(android.graphics.Typeface.BOLD), 29, 40, Spannable.SPAN_EXCLUSIVE_INCLUSIVE);

        view1.setText(style);