public static void SetValueToRtf(HtmlNode htmlNode, ref StringBuilder builder)
        {
            foreach (var attribute in htmlNode.Attributes)
            {
                if (attribute.Name == "style")
                {
                    var cssAttritues = new List <CssAttritue>();
                    cssAttritues = GetAttributesInfo(attribute.Value);

                    // 적용
                    foreach (var cssAttritue in cssAttritues)
                    {
                        foreach (var cssValue in cssAttritue.CssValues)
                        {
                            var rtfTuple = RtfSpec.GetRtfCodeFromCss(cssAttritue.AttributeName, cssValue.Value);

                            // 적용할 텍스트가 있는지 검사해서 있으면 적용
                            if (htmlNode.FirstChild.Name.Equals("#text") && !string.IsNullOrEmpty(htmlNode.FirstChild.InnerText.Trim()))
                            {
                                var valueText = new StringBuilder(htmlNode.FirstChild.InnerText);

                                valueText.Insert(0, rtfTuple.header);
                                valueText.Append(rtfTuple.footer);

                                builder.Append(valueText);
                            }
                        }
                    }
                }
                else if (attribute.Name == "class")
                {
                    var rtfTuples = GetRtfCodeFromClasses(attribute.Value);

                    // 적용할 텍스트가 있는지 검사해서 있으면 적용
                    if (htmlNode.FirstChild.Name.Equals("#text") && !string.IsNullOrEmpty(htmlNode.FirstChild.InnerText.Trim()))
                    {
                        var valueText = new StringBuilder(htmlNode.FirstChild.InnerText);
                        foreach (var rtfTuple in rtfTuples)
                        {
                            valueText.Insert(0, rtfTuple.header);
                            valueText.Append(rtfTuple.footer);
                        }
                        builder.Append(valueText);
                    }
                }
            }
        }
        public static List <(string header, string footer)> GetRtfCodeFromClasses(string _className)
        {
            var ps      = new List <(string header, string footer)>();
            var rtfCode = (header : "", footer : "");

            foreach (var cssClass in CssClasses)
            {
                if (cssClass.ClassName.Equals(_className))
                {
                    foreach (var cssAttritue in cssClass.CssAttritues)
                    {
                        foreach (var cssValue in cssAttritue.CssValues)
                        {
                            rtfCode = RtfSpec.GetRtfCodeFromCss(cssAttritue.AttributeName, cssValue.Value);
                            ps.Add(rtfCode);
                        }
                    }
                }
            }

            return(ps);
        }