如何在TextView中显示带有CSS类的HTML文本？

String htmlText = "<p><span class=\"red\">这是红色文本</span></p>";
Spanned spannedText = Html.fromHtml(htmlText);

public class CustomTagHandler implements Html.TagHandler {
    @Override
    public void handleTag(boolean opening, String tag, Editable output, XMLReader xmlReader) {
        if (tag.equalsIgnoreCase("span")) {
            handleSpanTag(opening, output);
        }
    }

    private void handleSpanTag(boolean opening, Editable output) {
        int len = output.length();
        if (opening) {
            output.setSpan(new ForegroundColorSpan(Color.RED), len, len, Spannable.SPAN_MARK_MARK);
        } else {
            Object obj = getLast(output, ForegroundColorSpan.class);
            int where = output.getSpanStart(obj);
            output.removeSpan(obj);
            if (where != len) {
                output.setSpan(new ForegroundColorSpan(Color.RED), where, len, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
    }

    private Object getLast(Editable text, Class kind) {
        Object[] spans = text.getSpans(0, text.length(), kind);
        if (spans.length == 0) {
            return null;
        } else {
            for (int i = spans.length; i > 0; i--) {
                if (text.getSpanFlags(spans[i - 1]) == Spannable.SPAN_MARK_MARK) {
                    return spans[i - 1];
                }
            }
            return null;
        }
    }
}

TextView textView = findViewById(R.id.textView);
textView.setText(spannedText);

Html.fromHtml(htmlText, null, new CustomTagHandler());