C # Regular Extraction Small example

Common grouping Syntax

category	Code/Syntax	Description
Capture	(exp)	Match exp, and capture text into an automatically named group
	(? <name>exp)	Match exp, and capture the text to a group named name, or you can write (? ') Name ' exp ')
	(?: EXP)	Matches exp, does not capture matching text, and does not assign group numbers to this group
0 Wide Assertion	(? =exp)	Match the position of the exp front
	(? <=exp)	Match the position after exp
	(?! Exp	Match the position followed by the exp.
	(? <!exp)	Match a location that is not previously exp
Comments	(? #comment)	This type of grouping does not have any effect on the processing of regular expressions, and is used to provide comments for people to read

Extract Payaccno in the middle of the account string input = @ "        <payaccno>6227000000000000001</payaccno>        <payaccname > Zhang San </payaccname>        <payaccno>6227000000000000002</payaccno>        <payaccname> John Doe </payaccname>                       "; Regex reg = new Regex (@ "(?<=<payaccno>) (\d+) (?=</payaccno>) +"), var matches = Reg. Matches (input); string result = ""; foreach (var m in Matches) {    result + = m + ",";} result = result. TrimEnd (', ');//Result: 6227007201840000001,6227007201840000002

C # Regular Extraction Small example