正则表达式替换捕获后按数字 [英] Regex replacement capture followed by digit

问题描述

我想获得一个正则表达式替换工作更新我的AssemblyInfo.cs文件，所以我有：

I am trying to get a Regex replacement working to update my AssemblyInfo.cs files, so I have:

Regex.Replace(
    contents, 
    @"(\[assembly: Assembly(File)?Version\("").*(""\)\])", 
    "$1" + version + "$3"
);

问题是，版本是像1.5.3.0，这样当更换评估这是一个看$ 11.5.3.0 $ 3是presumably寻找十一届捕获组，因为它是走出来：

The problem is that version is something like "1.5.3.0", so that when the replacement is evaluated it is seeing "$11.5.3.0$3" and is presumably looking for the eleventh captured group because it is coming out with:

$11.5.3.0")]

如果是后 $ 1棒的空间它工作正常。需要什么就摆在那里逃脱的第二位，而不实际插入字符？

If is stick a space after the $1 it works fine. What do I need to put in there to escape the second digit without actually inserting the character?

推荐答案

使用 $ {1} 而不是 $ 1 。这也是名为捕获组的替换语法 （小于？;名称＆gt;）

Use ${1} instead of $1. This is also the substitution syntax for named capturing group (?<name>).

下面是一个片段来说明（另见ideone.com ）：

Here's a snippet to illustrate (see also on ideone.com):

Console.WriteLine(Regex.Replace("abc", "(.)", "$11"));        // $11$11$11
Console.WriteLine(Regex.Replace("abc", "(.)", "${1}1"));      // a1b1c1
Console.WriteLine(Regex.Replace("abc", "(?<x>.)", "${x}1"));  // a1b1c1

此行​​为被明确记载：

This behavior is explicitly documented:

在 $号语言元素，包括所匹配的号码的后子捕获组在替换字符串，其中号是捕获组的索引。

Regular Expression Language Elements - Substitutions

Substituting a Numbered Group

The $number language element includes the last substring matched by the number capturing group in the replacement string, where number is the index of the capturing group.

如果号没有指定在常规EX pression模式定义的有效捕获组， $号是PTED为跨$ P $一个的文字字符序列的用于替换每个匹配。

If number does not specify a valid capturing group defined in the regular expression pattern, $number is interpreted as a literal character sequence that is used to replace each match.

在 $ {名} 语言元素替换匹配的名称捕获组，其中<$的最后一个子C $ C>名称是由定义的捕获组的名称（LT;名称＆gt;）语言元素

The ${name} language element substitutes the last substring matched by the name capturing group, where name is the name of a capturing group defined by the (?<name>) language element.

如果名称没有指定在常规EX pression模式定义了一个有效的命名捕获组， $ {名} 是PTED为的文字字符序列的用于替换每个匹配。

If name does not specify a valid named capturing group defined in the regular expression pattern, ${name} is interpreted as a literal character sequence that is used to replace each match.

这篇关于正则表达式替换捕获后按数字的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！