asp.net中如何把一个字符串中的所有html代码去掉成为文本模式

public string ClearHtml(string HtmlStr)

{

string tmpStr = HtmlStr;

tmpStr = ReplaceHtml("&#[^>]*;", tmpStr, "");

tmpStr = ReplaceHtml("</?marquee[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?object[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?param[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?embed[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?table[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml(" ", tmpStr, "");

tmpStr = ReplaceHtml("</?tr[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?th[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?p[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?a[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?img[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?tbody[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?li[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?span[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?div[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?th[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?td[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?script[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("(javascript|jscript|vbscript|vbs):", tmpStr, "");

tmpStr = ReplaceHtml("on(mouse|exit|error|click|key)", tmpStr, "");

tmpStr = ReplaceHtml("<\\?xml[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("<\\/?[a-z]+:[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?font[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?b[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?u[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?i[^>]*>", tmpStr, "");

tmpStr = ReplaceHtml("</?strong[^>]*>", tmpStr, "");

return tmpStr;

}

public string ReplaceHtml(string Pattern, string HtmlStr, string replacement)

{

System.Text.RegularExpressions.Regex rx = new System.Text.RegularExpressions.Regex(Pattern,System.Text.RegularExpressions.RegexOptions.IgnoreCase);

if(rx.IsMatch(HtmlStr))

return rx.Replace(HtmlStr, replacement);

return HtmlStr;

}