Question

有没有办法在C＃中获取被捕获组的名称？

string line = "No.123456789  04/09/2009  999";
Regex regex = new Regex(@"(?<number>[\d]{9})  (?<date>[\d]{2}/[\d]{2}/[\d]{4})  (?<code>.*)");

GroupCollection groups = regex.Match(line).Groups;

foreach (Group group in groups)
{
    Console.WriteLine("Group: {0}, Value: {1}", ???, group.Value);
}

我想得到这个结果：

Group: [I don´t know what should go here], Value: 123456789  04/09/2009  999
Group: number, Value: 123456789
Group: date,   Value: 04/09/2009
Group: code,   Value: 999

Answer 1

使用GetGroupNames获取表达式中的组列表，然后使用名称作为组集合中的键进行迭代。

例如，

GroupCollection groups = regex.Match(line).Groups;

foreach (string groupName in regex.GetGroupNames())
{
    Console.WriteLine(
       "Group: {0}, Value: {1}",
       groupName,
       groups[groupName].Value);
}

Answer 2

最简洁的方法是使用此扩展方法：

public static class MyExtensionMethods
{
    public static Dictionary<string, string> MatchNamedCaptures(this Regex regex, string input)
    {
        var namedCaptureDictionary = new Dictionary<string, string>();
        GroupCollection groups = regex.Match(input).Groups;
        string [] groupNames = regex.GetGroupNames();
        foreach (string groupName in groupNames)
            if (groups[groupName].Captures.Count > 0)
                namedCaptureDictionary.Add(groupName,groups[groupName].Value);
        return namedCaptureDictionary;
    }
}

一旦使用此扩展方法，您就可以获得如下名称和值：

    var regex = new Regex(@"(?<year>[\d]+)\|(?<month>[\d]+)\|(?<day>[\d]+)");
    var namedCaptures = regex.MatchNamedCaptures(wikiDate);

    string s = "";
    foreach (var item in namedCaptures)
    {
        s += item.Key + ": " + item.Value + "\r\n";
    }

    s += namedCaptures["year"];
    s += namedCaptures["month"];
    s += namedCaptures["day"];

Answer 3

您应该使用GetGroupNames();，代码看起来像这样：

    string line = "No.123456789  04/09/2009  999";
    Regex regex = 
        new Regex(@"(?<number>[\d]{9})  (?<date>[\d]{2}/[\d]{2}/[\d]{4})  (?<code>.*)");

    GroupCollection groups = regex.Match(line).Groups;

    var grpNames = regex.GetGroupNames();

    foreach (var grpName in grpNames)
    {
        Console.WriteLine("Group: {0}, Value: {1}", grpName, groups[grpName].Value);
    }

Answer 4

从.NET 4.7开始，Group.Name属性为available。

Answer 5

正则表达式是这个的关键！

foreach(Group group in match.Groups)
{
    Console.WriteLine("Group: {0}, Value: {1}", regex.GroupNameFromNumber(group.Index), group.Value);
}

http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.groupnamefromnumber.aspx

如何在C＃Regex中获取捕获组的名称？

5 个答案: