.NET中命名捕获组的正则表达式模式是什么？

Question

I'm struggling with a regex pattern that will pull out text from a string into named groups.

A (somewhat arbitrary) example will best explain what I'm trying to achieve.

string input =
    "Mary Anne has been to 949 bingo games. The last was on Tue 24/04/2012. She won with the Numbers: 4, 6, 11, 16, 19, 27, 45";

string pattern =
    @"(?<Person>\w+?) has been to (?<NumberOfGames>\d+?) bingo games. The last was on (?<Day>...?) (?<Date>...?). She won with the Numbers: (?<Numbers>...?)";

Regex regex = new Regex(pattern);
var match = regex.Match(input);

string person = match.Groups["Person"].Value;
string noOfGames = match.Groups["NumberOfGames"].Value;
string day = match.Groups["Day"].Value;
string date = match.Groups["Date"].Value;
string numbers = match.Groups["Numbers"].Value;

I can't seem to get the regex pattern to work, but i think the above explains it well enough. Essentially i need to get the person name, the number of games etc.

Can anyone solve this and explain the actual regex pattern they worked out?

Answer 1

 string pattern = @"(?<Person>[\w ]+) has been to (?<NumberOfGames>\d+) bingo games\. The last was on (?<Day>\w+) (?<Date>\d\d/\d\d/\d{4})\. She won with the Numbers: (?<Numbers>.*?)$";

其他帖子提到了如何拉出组，但这个正则表达式匹配您的输入。

Answer 2

Have a look at the documentation for Result() :

Returns the expansion of the specified replacement pattern.

You don't want any replacement patterns, so this method is not the right solution.

You want to access groups of the match, so do that: there is a Groups property .

With that your code would look like this:

string title = match.Groups["Person"].Value;
string drawNumber = match.Groups["NumberOfGames"].Value;

Also, as russau correctly pointed out, your pattern doesn't match your text: Date is not just three characters.

Answer 3

Try this:

string pattern = @"(?<Person>\w+?) has been to (?<NumberOfGames>\d+?) bingo games. The last was on (?<Day>...?) (?<Date>\d+/\d+/\d+). She won with the Numbers: (?<Numbers>...?)";

Your regex isn't matching the date part of the string.

Answer 4

Assuming the regex works the code for getting the named group would be this:

string title = match.Groups["Person"].Value;
string drawNumber = match.Groups["NumberOfGames"].Value;