System.Xml.XmlConvert.IsXmlChar C# (CSharp) Method

        public static unsafe bool IsXmlChar(char ch)
        {
            return s_xmlCharType.IsCharData(ch);
        }

        static string RemoveInvalidXmlChars(string text)
        {
            var validXmlChars = text.Where(ch => XmlConvert.IsXmlChar(ch)).ToArray();

            return(new string(validXmlChars));
        }