在正文抽取（正文提取）裏一般會用到的正則，易爾譯科技收集了一下，是C#版本的正文抽取正則表達式。歡迎大家補充。
#region 相關正則表達式
/// <summary>
/// 去掉所有html標籤
/// </summary>
private static readonly Regex FilterAll = new Regex(
@"(/[([^=]*)(=[^/]]*)?/][/s/S]*?/[//1/])|(?<lj>(?=[^/u4E00-/u9FA5/uFE30-/uFFA0,."");])<a/s+[^>]*>[^<]{2,}</a>(?=[^/u4E00-/u9FA5/uFE30-/uFFA0,."");]))|(?<Style><style[/s/S]+?/style>)|(?<select><select[/s/S]+?/select>)|(?<Script><script[/s/S]*?/script>)|(?<Explein></!/-/-[/s/S]*?/-/->)|(?<li><li(/s+[^>]+)?>[/s/S]*?/li>)|(?<Html></?/s*[^> ]+(/s*[^=>]+?=['""]?[^""']+?['""]?)*?[^/[<]*>)|(?<Other>&[a-zA-Z]+;)|(?<Other2>/#[a-z0-9]{6})|(?<Space>/s+)|(/&/#/d+/;)",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase); //(?<Link><a[/s/S]*?</a>)|
//(?<Style><style[/s/S]+?/style>)|(?<select><select[/s/S]+?/select>)|(?<Script><script[/s/S]*?/script>)|(?<Explein></!/-/-[/s/S]*?/-/->)|(?<li><li(/s+[^>]+)?>[/s/S]*?/li>)|(?<Html></?/s*[^> ]+(/s*[^=>]+?=['""]?[^""']+?['""]?)*?[^/[<]*>)|(?<Other>&[a-zA-Z]+;)|(?<Other2>/#[a-z0-9]{6})|(?<Space>/s+)
/// <summary>
/// 找出title標籤
/// </summary>
private static readonly Regex FindTitle = new Regex(
@"</s*/?title/s*>",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出title標籤內容
/// </summary>
private static readonly Regex FindTitleContent = new Regex(
@"</s*/?title/s*>(?<Content>[/s/S]*?)</s*/?title/s*>",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出h 和Strong標籤
/// </summary>
private static readonly Regex FindHStrong = new Regex(
@"</s*/?h/s*>|</s*/?strong/s*>",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出p 和br標籤
/// </summary>
private static readonly Regex FindPB = new Regex(
@"</s*/?p/s*>|</s*br/s*/?>|</s*/?tr/s*>",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出nbsp標籤
/// </summary>
private static readonly Regex FindNbsp = new Regex(
@" ",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出結尾標籤
/// </summary>
private static readonly Regex FindS = new Regex(
@"(?<Content>[/s/S]*?)/$",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出是否爲標準句
/// </summary>
private static readonly Regex IsSen = new Regex(
@"[,.，。!！;；:：……？?《》“”""]",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出是否爲垃圾句[strong][h]標籤過多的
/// </summary>
private static readonly Regex IsWs = new Regex(
@"/[/(h/)/]",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出是否爲垃圾句冒號和·-過多的
/// </summary>
private static readonly Regex IsWsM = new Regex(
@"/[·]|[－]|[：:]",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出是否爲BBS特徵
/// </summary>
private static readonly Regex IsBbsInfo = new Regex(
@"第[^樓]{1,50}樓|Powered/s*/?by[/s/S]*?Dvbbs|Powered/s*/?by[/s/S]*?Discuz",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 取KEYWORD
/// </summary>
private static readonly Regex mKeyWord = new Regex(
@"<meta/s*name/s*=/s*['""]?keywords['""]?/s*content/s*=/s*['""]?(?<KeyWords>[^'"">]*)['""]?[^>]*>|<meta/s*content/s*=/s*['""]?(?<KeyWords>[^'"">]*)['""]?/s*name/s*=/s*['""]?keywords['""]?/s*[^>]*>
",RegexOptions.ExplicitCapture| RegexOptions.Multiline| RegexOptions.IgnoreCase);
/// <summary>
/// 取DESCRIPTION
/// </summary>
private static readonly Regex mDescription = new Regex(
@"<meta/s*name/s*=/s*['""]?description['""]?/s*content/s*=/s*['""]?(?<description>[^'"">]*)['""]?[^>]*>|<meta/s*content/s*=/s*['""]?(?<description>[^'"">]*)['""]?/s*name/s*=/s*['""]?description['""]?/s*[^>]*>
",RegexOptions.ExplicitCapture| RegexOptions.Multiline| RegexOptions.IgnoreCase);
/// <summary>
/// 取Tags
/// </summary>
private static readonly Regex mTag = new Regex(
@"<meta/s*name/s*=/s*['""]?tagwords['""]?/s*content/s*=/s*['""]?(?<tagwords>[^'"">]*)['""]?[^>]*>|<meta/s*content/s*=/s*['""]?(?<tagwords>[^'"">]*)['""]?/s*name/s*=/s*['""]?tagwords['""]?/s*[^>]*>
", RegexOptions.ExplicitCapture | RegexOptions.Multiline | RegexOptions.IgnoreCase);
/// <summary>
/// 找出是否爲垃圾句:後字符號過少，：號前無“說”字,:號後無"關於"
/// </summary>
private static readonly Regex IsWsMM = new Regex(
@"^[^說/s]{0,8}?[:：].{0,10}$",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出spider寫入的url標記
/// </summary>
private static readonly Regex txtUrl = new Regex(
@"當前URL爲:http://(?<URL>.*)",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
/// <summary>
/// 找出spider寫入的錨點描述標記
/// </summary>
private static readonly Regex txtDescription = new Regex(
@"當前鏈接描述爲:(?<Describe>.*)",
RegexOptions.ExplicitCapture
| RegexOptions.Multiline
| RegexOptions.IgnoreCase);
///// <summary>
///// 取需要a標籤
///// </summary>
//private static readonly Regex cleanFirst = new Regex(
// @"([/u4E00-/u9FA5]|[/uFE30-/uFFA0]|[,."");])(?<Robbish1><a/s+[^>]*>)[^<]{1,6}(?<Robbish2></a>)([/u4E00-/u9FA5]|[/uFE30-/uFFA0]|[,."");])", RegexOptions.ExplicitCapture | RegexOptions.Multiline | RegexOptions.IgnoreCase);
#endregion