C#替换html实体

        /// <summary>
        /// convert special char to html entity
        /// </summary>
        /// <param name="source">source string</param>
        /// <returns>target string</returns>
        public static string ToHtmlEntity(string source)
        {
            if (string.IsNullOrEmpty(source))
            {
                return string.Empty;
            }

            string result = source.Replace("\"", "&quot;"); // "
            result = result.Replace("'", "'"); // '--> &apos;
            result = result.Replace("<", "&lt;"); // <
            result = result.Replace(">", "&gt;"); // >
            result = result.Replace("&", "&amp;"); // &

            return result;
        }