android上实现富文本

SpannableString s = new SpannableString("MPAndroidChart developed\n by Philipp Jahoda");
s.setSpan(new RelativeSizeSpan(1.7f), 0, 14, 0);
s.setSpan(new StyleSpan(Typeface.NORMAL), 14, s.length() - 15, 0);
s.setSpan(new ForegroundColorSpan(Color.GRAY), 14, s.length() - 15, 0);
s.setSpan(new RelativeSizeSpan(.8f), 14, s.length() - 15, 0);
s.setSpan(new StyleSpan(Typeface.ITALIC), s.length() - 14, s.length(), 0);
s.setSpan(new ForegroundColorSpan(ColorTemplate.getHoloBlue()), s.length() - 14, s.length(), 0);