textView.getPaint().setFlags(Paint.UNDERLINE_TEXT_FLAG);// 下劃線
//這種寫法可以抗鋸齒:
SpannableString content = new SpannableString("註冊新賬號");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
registTV.setText(content);
textView.getPaint().setFlags(Paint.UNDERLINE_TEXT_FLAG);// 下劃線
//這種寫法可以抗鋸齒:
SpannableString content = new SpannableString("註冊新賬號");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
registTV.setText(content);