c# - 正则表达式字符串，但有几个选项

Question

我的字符串:

string str = "user:steo id:1 nickname|user:kevo id:2 nickname:kevo200|user:noko id:3 nickname";

现在我想用正则表达式得到值:

var reg = Regex.Matches(str, @"user:(.+?)\sid:(\d+)\s+nickname:(.+?)")
          .Cast<Match>()
          .Select(a => new
          {
              user = a.Groups[1].Value,
              id = a.Groups[2].Value,
              nickname = a.Groups[3].Value
           })
           .ToList();
foreach (var ca in reg)
{
    Console.WriteLine($"{ca.user} id: {ca.id} nickname: {ca.nickname}");
}  

我不知道如何使用正则表达式来实现 nickname:(the nickname) 我只想使用昵称，如果它有一个像 nickname:kevo200 和 noch 昵称

Answer 1

我不是 100% 确定这是否回答了您的问题，但我通过正则表达式解析从给定的输入字符串中获取了一个列表，并在可用时返回昵称或否则返回用户名。

PS C:\WINDOWS\system32> scriptcs
> using System.Text.RegularExpressions;
> var regex = new Regex(@"\|?(?:user(?::?(?<user>\w+))\sid(?::?(?<id>\d*))\s?nickname(?::?(?<nick>\w+))?)");
> var matches = regex.Matches("user:steo id:1 nickname|user:kevo id:2 nickname:kevo200|user:noko id:3 nickname");
> matches.Cast<Match>().Select(m=>new {user=m.Groups["user"].Value,nick=m.Groups["nick"].Value}).Select(u=>string.IsNullOrWhiteSpace(u.nick)?u.user:u.nick);
[
  "steo",
  "kevo200",
  "noko"
]

编辑:正则表达式设计器:https://regexr.com/3uf8t

编辑:改进版本以接受昵称中的转义序列

PS C:\WINDOWS\system32> scriptcs
> using System.Text.RegularExpressions;
> var regex = new Regex(@"\|?(?:user(?::(?<user>\w+))?\sid(?::(?<id>\d*))?\s?nickname(?::(?<nick>[\w\\]+))?)");
> var matches = regex.Matches("user:steo id:1 nickname|user:kevo id:2 nickname:kevo200|user:noko id:3 nickname|user:kevo id:2 nickname:kev\\so200");
> matches.Cast<Match>().Select(m=>new {user=m.Groups["user"].Value,nick=m.Groups["nick"].Value.Replace("\\s"," ")}).Select(u=>string.IsNullOrWhiteSpace(u.nick)?u.user:u.nick);
[
  "steo",
  "kevo200",
  "noko",
  "kev o200"
]