. NET regular expression syntax use case

Character matching syntax:

character Syntax	Grammar explanation	Syntax Examples
\d	Matching digits (0~9)	' \d ' matches 8, does not match 12;
\d	Match non-numeric	' \d ' matches C, does not match 3;
\w	Match any single word character	' \w\w ' matches A3, does not match @3;
\w	Matching non-single character	' \w ' matches @, does not match C;
\s	Match White-space characters	' \d\s\d ' matches 3 D, does not match ABC;
\s	Match non-null characters	' \s\s\s ' matches a#4, does not match 3 D;
.	Match any character	' ... ' matches a$ 5, does not match line-wrapping;
[...]	Match any character in parentheses	[b-d] matches B, C, D, and does not match E;
[^ ...]	Matching non-bracket characters	[^b-z] matches a, does not match the b-z character;

Repeat match syntax:

repeating Syntax	Grammar explanation	Syntax Examples
N	Match N-th characters	\d{3} matches \d\d\d, does not match \d\d or \d\d\d\d
{N,}	Match n times and N times above	\W{2} matches \w\w and \w\w\w above, does not match \w
{N,m}	Match n times above M times	\s{1,3} matches \s,\s\s,\s\s\s and does not match \s\s\s\s
?	Match 0 or 1 times	5? Matches 5 or 0, does not match non 5 and 0
+	Match one or more times	\s+ matches more than one \s and does not match more than one \s
*	Match more than 0 times	\w* matches more than 0 \w, does not match non n*\w

Character positioning Syntax:

repeating Syntax	Grammar explanation	Syntax Examples
^	Locate back mode start position
$	The previous mode is at the end of the string
\a	Front mode start position
\z	Front mode End Position
\z	Front mode end position (before wrapping)
\b	Match a word boundary
\b	Match a non-word boundary

Escape matching syntax:

Escape Syntax	involving characters (grammar interpretation)	Syntax Examples
"\" + Actual character	\ . * + ? | ( ) { }^ $	Example: \ match character "\"
\ n	Match Line Wrap
\ r	Match carriage return
\ t	Match Horizontal Tab
\v	Match Vertical Tab
\f	Match page Change
\nnn	Matches a 8-in-system ASCII
\xnn	Matches a 16-in-system ASCII
\unnnn	Match 4-Uniode 16-binary
\c+ Capital Letter	Match Ctrl-Capital	For example: \cs-matching Ctrl+s

Example:

Read the file contents and analysis, the file format is as follows:

String[] lines = File.ReadAllLines (Server.MapPath ("Type.txt"), Encoding.UTF8); Regex Myregex = new Regex (@ ' ([\w\w]+) ' [\w\w]+ ' ([\w\w]+) ' [\w\w]+ ')]; Match match; foreach (string line in lines) { Response.Write (line + "<br/>"); Match = Myregex. Match (line); if (match. Success) { Response.Write ("Case \". "+match.") GROUPS[1]. Value + "\:<br/>");//Match 1th Response.Write ("ContentType = \" "+match.) GROUPS[2]. Value + "\;<br/>break;<br/>");//Match 2nd } }

The results of the run:

So, the regular expression is very powerful, especially when the batch format is very convenient to use.

Report:

Replace the keyword in the HTML code, but not the contents of the IMG a tag:

Html=regex.replace (html,@) (<! ( ]*?) | <a\b[^>]*?>[^<>]*?) (Design | skills) "," <a href=\ "http://www.test.com\" >$2</a> ");

Repeat what you want to match:

  var txt= "[cq:image,file=a7d637e6f29f199d7d2addeb2a1d21b4.png][cq:image,file= A7d637e6f29f199d7d2addeb2a1d21b5.png]adad ";
  Regex reg=new Regex (@ "\[cq:image,file= (? <filename>[^\s\r\n\]]+) \]", regexoptions.ignorecase);
  MatchCollection matches = Reg. Matches (TXT);
 if (matches. count>0) {
 matches. Count.dump ();
 foreach (match match in matches)
 {
 match. groups["FileName"]. Value.dump ();
 }
Else "Match failed." Dump ();

More regular expression references: http://blog.csdn.net/dl020840504/article/details/8880603