在按钮点击内尝试这样的事情.
TextView tv = (TextView) view.findViewById(R.id.tv);
SpannableString content = new SpannableString("Content");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
tv.setText(content);
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或尝试这个
textview.setPaintFlags(textview.getPaintFlags()| Paint.UNDERLINE_TEXT_FLAG);
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