.net - 正则表达式替换捕获后跟数字

Question

我正在尝试使用正则表达式替换来更新我的 AssemblyInfo.cs 文件，所以我有:

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

问题是 version 类似于 "1.5.3.0"，因此当评估替换时，它会看到 "$11.5.3.0$3" 并且可能正在寻找第十一个捕获的组，因为它出现了:

$11.5.3.0")]

如果在 $1 之后添加一个空格，则可以正常工作。我需要在那里输入什么来转义第二个数字而不实际插入字符？

Answer 1

使用${1}而不是$1 。这也是命名 capturing group 的替换语法(?<name>) .

这里有一个片段来说明( 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

此行为已明确记录:

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.

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.

Substituting a Named Group

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.

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.