一个用C#过滤HTML代码的函数

 public string checkStr(string html)
       {
           System.Text.RegularExpressions.Regex regex1 = new System.Text.RegularExpressions.Regex(@"<script[/s/S]+</script *>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex2 = new System.Text.RegularExpressions.Regex(@" href *= *[/s/S]*script *:", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex3 = new System.Text.RegularExpressions.Regex(@" no[/s/S]*=", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex4 = new System.Text.RegularExpressions.Regex(@"<iframe[/s/S]+</iframe *>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex5 = new System.Text.RegularExpressions.Regex(@"<frameset[/s/S]+</frameset *>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex6 = new System.Text.RegularExpressions.Regex(@"/<img[^/>]+/>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex7 = new System.Text.RegularExpressions.Regex(@"</p>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex8 = new System.Text.RegularExpressions.Regex(@"<p>", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
           System.Text.RegularExpressions.Regex regex9 = new System.Text.RegularExpressions.Regex(@"<[^>]*>", System.Text.RegularExpressions.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 = regex5.Replace(html, ""); //过滤frameset
           html = regex6.Replace(html, ""); //过滤frameset
           html = regex7.Replace(html, ""); //过滤frameset
           html = regex8.Replace(html, ""); //过滤frameset
           html = regex9.Replace(html, "");
           html = html.Replace(" ", "");
           html = html.Replace("</strong>", "");
           html = html.Replace("<strong>", "");
           return html;
}