出处：RegExLib.com Regular Expression Cheat Sheet (.NET)

元字符 说明 ^ 匹配字符串的开始位置 $ 匹配字符串的结束位置 . 匹配任意单个字符（换行符 \n 除外） | 交替 {…} 指定要限定的数量 [...] 指定要匹配的字符集 (…) 对表达式进行逻辑分组 * 匹配零或多个前面的表达式 + 匹配一或多个前面的表达式 ? 匹配零或一个前面的表达式 放在上面任何一个字符之前，表示匹配该字符本身。放在其他特殊字符后面，表示字符转义（见下面） 字符转义 说明 原始字符 除 . $ ^ { [ ( | ) ] } * + ? \ 之外的字符均匹配自身 \a 匹配铃声（闹铃）\u0007 \b 在[]中匹配一个空格 \u0008，在其他情况下匹配字边界（位于 \w 和 \W 字符之间） \t 匹配制表符 \u0009 \r 匹制回车符 \u000D \v 匹配垂直制表符 \u000B \f 匹配换页符 \u000C \n 匹配换行符 \u000A \e 匹配退出键（符） \u001B \040 匹配以八进制表示的 ASCII 字符（最多三位数）；在没有前导零的情况下，如果只有一位数字或者相应数字与某个捕获组的编号对应，那就是反向引用（backreference）。字符 \040 表示一个空格。 \x20 匹配以十六进制表示的 ASCII 字符（两位数） \cC 匹配 ASCII 控制符，例如 \cC 匹配 Ctrl+C \u0020 匹配以十六进制表示的 Unicode 字符 \* 反斜杠后面如果不是一个可转义的字符，则匹配该字符本身。例如，\* 就相当于\x2A 字符类 说明 . 匹配除 \n 之外的任意字符。 [aeiou] 匹配特定字符集中包含的任意一个字符 [^aeiou] 匹配特定字符集中不包含的任意一个字符 [0-9a-fA-F] 连字符（-）用来指定连续的字符范围 \p{name} 匹配由{name}指定的命名字符类中的任意字符 \P{name} 匹配不包含在{name}指定的组或块范围中的文本 \w 匹配英文数字字母字符，在指定兼容ECMAScript的情况下，等价于[a-zA-Z0-9] \W 匹配非英文数字字母字符，在指定兼容ECMAScript的情况下，等价于[^a-zA-Z0-9] \s 匹配任意空白字符，在指定兼容ECMAScript的情况下，等价于[\f\n\r\t\v] \S 匹配任意非空白字符，在指定兼容ECMAScript的情况下，等价于[^\f\n\r\t\v] \d 匹配数字字符，在指定兼容ECMAScript的情况下，等价于[0-9] \D 匹配非数字字符，在指定兼容ECMAScript的情况下，等价于[^0-9]
英文版:

Metacharacters Defined

MChar Definition ^ Start of a string. $ End of a string. . Any character (except \n newline) | Alternation. {...} Explicit quantifier notation. [...] Explicit set of characters to match. (...) Logical grouping of part of an expression. * 0 or more of previous expression. + 1 or more of previous expression. ? 0 or 1 of previous expression; also forces minimal matching when an expression might match several strings within a search string. Preceding one of the above, it makes it a literal instead of a special character. Preceding a special matching character, see below.

Metacharacter Examples

Pattern Sample Matches ^abc abc, abcdefg, abc123, ... abc$ abc, endsinabc, 123abc, ... a.c abc, aac, acc, adc, aec, ... bill|ted ted, bill ab{2}c abbc a[bB]c abc, aBc (abc){2} abcabc ab*c ac, abc, abbc, abbbc, ... ab+c abc, abbc, abbbc, ... ab?c ac, abc a\sc a c

Character Escapes http://tinyurl.com/5wm3wl

Escaped Char Description ordinary characters Characters other than . $ ^ { [ ( | ) ] } * + ? \ match themselves. \a Matches a bell (alarm) \u0007. \b Matches a backspace \u0008 if in a []; otherwise matches a word boundary (between \w and \W characters). \t Matches a tab \u0009. \r Matches a carriage return \u000D. \v Matches a vertical tab \u000B. \f Matches a form feed \u000C. \n Matches a new line \u000A. \e Matches an escape \u001B. \040 Matches an ASCII character as octal (up to three digits); numbers with no leading zero are backreferences if they have only one digit or if they correspond to a capturing group number. (For more information, see Backreferences.) For example, the character \040 represents a space. \x20 Matches an ASCII character using hexadecimal representation (exactly two digits). \cC Matches an ASCII control character; for example \cC is control-C. \u0020 Matches a Unicode character using a hexadecimal representation (exactly four digits). \* When followed by a character that is not recognized as an escaped character, matches that character. For example, \* is the same as \x2A.

Character Classes http://tinyurl.com/5ck4ll

Char Class Description . Matches any character except \n. If modified by the Singleline option, a period character matches any character. For more information, see Regular Expression Options. [aeiou] Matches any single character included in the specified set of characters. [^aeiou] Matches any single character not in the specified set of characters. [0-9a-fA-F] Use of a hyphen (–) allows specification of contiguous character ranges. \p{name} Matches any character in the named character class specified by {name}. Supported names are Unicode groups and block ranges. For example, Ll, Nd, Z, IsGreek, IsBoxDrawing. \P{name} Matches text not included in groups and block ranges specified in {name}. \w Matches any word character. Equivalent to the Unicode character categories [\p{Ll}\p{Lu}\p{Lt}\p{Lo}\p{Nd}\p{Pc}]. If ECMAScript-compliant behavior is specified with the ECMAScript option, \w is equivalent to [a-zA-Z_0-9]. \W Matches any nonword character. Equivalent to the Unicode categories [^\p{Ll}\p{Lu}\p{Lt}\p{Lo}\p{Nd}\p{Pc}]. If ECMAScript-compliant behavior is specified with the ECMAScript option, \W is equivalent to [^a-zA-Z_0-9]. \s Matches any white-space character. Equivalent to the Unicode character categories [\f\n\r\t\v\x85\p{Z}]. If ECMAScript-compliant behavior is specified with the ECMAScript option, \s is equivalent to [ \f\n\r\t\v]. \S Matches any non-white-space character. Equivalent to the Unicode character categories [^\f\n\r\t\v\x85\p{Z}]. If ECMAScript-compliant behavior is specified with the ECMAScript option, \S is equivalent to [^ \f\n\r\t\v]. \d Matches any decimal digit. Equivalent to \p{Nd} for Unicode and [0-9] for non-Unicode, ECMAScript behavior. \D Matches any nondigit. Equivalent to \P{Nd} for Unicode and [^0-9] for non-Unicode, ECMAScript behavior.