把文本解析为htm代码的一段代码

 

    /// <summary>
        /// HTML编码
        /// </summary>
        /// <param name="Htmlstring"></param>
        /// <returns></returns>
        private static Regex reg = new Regex(@"[<>&\r\n\t ]", RegexOptions.IgnoreCase | RegexOptions.Compiled);
        public static string HtmlCode(string s)
        {
            s = reg.Replace(s, new MatchEvaluator(delegate(Match m)
            {
                switch (m.ToString())
                {
                    case "<":
                        return "&lt;";
                    case ">":
                        return "&gt;";
                    case "&":
                        return "&amp;";
                    case "\r":
                        return "\r";
                    case "\n":
                        return "\n<br />";
                    case "\t":
                        return "&nbsp;&nbsp;&nbsp;&nbsp;";
                    case " ":
                        return "&nbsp;";
                    default:
                        return m.ToString();
                }
            }));
            return s;
        }