C#实现HTML和UBB互相转换的方法

    _Html = Regex.Replace(_Html, "<br[^>]*>", "\n");
    _Html = Regex.Replace(_Html, @"<p[^>\/]*\/>", "\n");
    _Html = Regex.Replace(_Html, "\\son[\\w]{3,16}\\s?=\\s*([\'\"]).+?\\1", "");
    _Html = Regex.Replace(_Html, "<hr[^>]*>", "[hr]");

    _Html = Regex.Replace(_Html, "<(\\/)?blockquote([^>]*)>", "[$1blockquote]");
    _Html = Regex.Replace(_Html, "<img[^>]*smile=\"(\\d+)\"[^>]*>", "'[s:$1]");
    _Html = Regex.Replace(_Html, "<img[^>]*src=[\'\"\\s]*([^\\s\'\"]+)[^>]*>", "");
    _Html = Regex.Replace(_Html, "<a[^>]*href=[\'\"\\s]*([^\\s\'\"]*)[^>]*>(.+?)<\\/a>", "[url=$1]$2[/url]");
    _Html = Regex.Replace(_Html, "<b>(.+?)</b>",@"\[b\]$1\[/b\]");
    _Html = Regex.Replace(_Html, "<[^>]*?>", "");
    _Html = Regex.Replace(_Html, "&", "&");
    _Html = Regex.Replace(_Html, " ", " ");
    _Html = Regex.Replace(_Html, "<", "<");
    _Html = Regex.Replace(_Html, ">", ">");

    return _Html;
}
public string ubbtohtml(string content)  //ubb转html
{
    content = Regex.Replace(content, @"\r\n", "<br/>");
    content = Regex.Replace(content, " ", " ");
    content = Regex.Replace(content, @"\[b\](.+?)\[/b\]", "<b>$1</b>");
    content = Regex.Replace(content, @"\[i\](.+?)\[/i\]", "<i>$1</i>");
    content = Regex.Replace(content, @"\[u\](.+?)\[/u\]", "<u>$1</u>");
    content = Regex.Replace(content, @"\[p\](.+?)\[/p\]", "<p class='load'>$1</p>");
    content = Regex.Replace(content, @"\[align=left\](.+?)\[/align\]", "<align='left'>$1</align>");
    content = Regex.Replace(content, @"\[align=center\](.+?)\[/align\]", "<align='center'>$1</align>");
    content = Regex.Replace(content, @"\[align=right\](.+?)\[/align\]", "<align='right'>$1</align>");
    content = Regex.Replace(content, @"\[url=(?<url>.+?)]\[/url]", "<a href='${url}' target=_blank>${url}</a>");
    content = Regex.Replace(content, @"\[url=(?<url>.+?)](?<name>.+?)\[/url]", "<a href='${url}' target=_blank>${name}</a>");
    content = Regex.Replace(content, @"\[quote](?<text>.+?)\[/quote]", "<div class="quote">${text}</div>");
    content = Regex.Replace(content, @"\[img](?<img>.+?)\[/img]", "<img src='${img}' alt=''/>");
    return content;
}