Use regular expressions in C # To automatically match and obtain the required data.

Regular Expressions can match various types of data (such as e-mail addresses, phone numbers, and identity numbers) according to the settings ). Regular Expressions are powerful and flexible to use. C #, Java, JavaScript, and other languages support regular expressions. Regular Expressions are indispensable for "capturing data" on the Internet. Today, I want to talk about using regular expressions in C # To automatically match and obtain the required data.

The following is a part (string) of the query result returned by an IP address query website. Now, you need to obtain "query result 1:" followed by "Beijing Netcom" from this string ". < TD Align = "Center" > < Ul > < Li > Query Result 1: Beijing Netcom </ Li > < Li > Query Result 2: Beijing Netcom </ Li > < Li > Query Result 3: Beijing Netcom </ Li > </ Ul > </ TD >

C # related Code As follows:String Srcstring =   " <TD align = \ " Center \ " > <Ul> <li> query result 1: Beijing Netcom </LI> <li> query result 2: Beijing Netcom </LI> <li> query result 3: beijing Netcom </LI> </ul> </TD> " ;
//Match the regular expression of all characters between "<li> query result 1:" and "</LI>"
String Regexstr =   " <Li> query result 1 :(? <Key> .*?) </LI> " ;
RegEx R =   New RegEx (regexstr, regexoptions. None );
Match MC = R. Match (srcstring );
StringDatastr = Mc. Groups [ " Key " ]. Value;

Note:
The most important thing here is to set a regular expression:"<Li> query result 1 :(? <Key> .*?) </LI>".

character	description
	Based on key gets the value matched by a regular expression.
.	Except " \ n " .
*	match the previous subexpression zero or multiple times .
?	follows any other delimiter (*, + ,?, {N },{ n ,},{ n, m}) later, the matching mode is not greedy ; the non-Greedy mode matches as few searched strings as possible, while the default greedy mode matches as many searched strings as possible.

Datastr is the data we need: "Beijing Netcom ".

From: http://www.cnblogs.com/anjou/archive/2007/03/20/681744.html