对用户提交的恶意代码进行处理

        /// <summary>
        /// Method to make sure that user's inputs are not malicious
        /// </summary>
        /// <param name="text">User's Input</param>
        /// <param name="maxLength">Maximum length of input</param>
        /// <returns>The cleaned up version of the input</returns>
        public static string InputText(string text, int maxLength) {
            text = text.Trim();
            if (string.IsNullOrEmpty(text))
                return string.Empty;
            if (text.Length > maxLength)
                text = text.Substring(0, maxLength);
            text = Regex.Replace(text, "[\\s]{2,}", " ");    //two or more spaces
            text = Regex.Replace(text, "(<[b|B][r|R]/*>)+|(<[p|P](.|\\n)*?>)", "\n");    //<br>
            text = Regex.Replace(text, "(\\s*&[n|N][b|B][s|S][p|P];\\s*)+", " ");    //&nbsp;
            text = Regex.Replace(text, "<(.|\\n)*?>", string.Empty);    //any other tags
            text = text.Replace("'", "''");
            return text;
        }

摘自PetShop