c# 正则格式化文本防止SQL注入

 /// <summary>
        /// 格式化文本（防止SQL注入）
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string Formatstr(string html)
        {
            Regex regex1 = new Regex(@"<script[sS]+</script *>", RegexOptions.IgnoreCase);
            Regex regex2 = new Regex(@" href *= *[sS]*script *:",RegexOptions.IgnoreCase);
            Regex regex3 = new Regex(@" on[sS]*=",RegexOptions.IgnoreCase);
            Regex regex4 = new Regex(@"<iframe[sS]+</iframe *>", RegexOptions.IgnoreCase);
            Regex regex5 = new Regex(@"<frameset[sS]+</frameset *>",RegexOptions.IgnoreCase);
            Regex regex10 = new Regex(@"select", RegexOptions.IgnoreCase);
            Regex regex11 = new Regex(@"update", RegexOptions.IgnoreCase);
            Regex regex12 = new Regex(@"delete", RegexOptions.IgnoreCase);
            html = regex1.Replace(html, ""); //过滤<script></script>标记
            html = regex2.Replace(html, ""); //过滤href=javascript: (<A>) 属性
            html = regex3.Replace(html, " _disibledevent="); //过滤其它控件的on...事件
            html = regex4.Replace(html, ""); //过滤iframe
            html = regex10.Replace(html, "s_elect");
            html = regex11.Replace(html, "u_pudate");
            html = regex12.Replace(html, "d_elete");
            html = html.Replace("'", "’");
            html = html.Replace("&nbsp;", " ");
            return html;
        }