将匹配结果从正则表达式转换为字符串列表

Question

如何将匹配结果列表从正则表达式转换为List<string>？我有这个功能,但它总是会产生异常,

无法将类型为"System.Text.RegularExpressions.Match"的对象强制转换为"System.Text.RegularExpressions.CaptureCollection".

public static List<string> ExtractMatch(string content, string pattern)
{
    List<string> _returnValue = new List<string>();
    Match _matchList = Regex.Match(content, pattern);
    while (_matchList.Success)
    {
        foreach (Group _group in _matchList.Groups)
        {
            foreach (CaptureCollection _captures in _group.Captures) // error
            {
                foreach (Capture _cap in _captures)
                {
                    _returnValue.Add(_cap.ToString());
                }
            }
        }
    }
    return _returnValue;
}

如果我有这个字符串,

I have a dog and a cat.

正则表达式

dog|cat

我希望函数将结果返回到 List<string>

dog
cat

Answer 1

使用正则表达式,您需要使用Regex.Matches以获得您想要的最终字符串列表:

MatchCollection matchList = Regex.Matches(Content, Pattern);
var list = matchList.Cast<Match>().Select(match => match.Value).ToList();

Answer 2

通过正则表达式匹配交叉发布回答-

要获得正则表达式匹配列表,您可以:

var lookfor = @"something (with) multiple (pattern) (groups)";
var found = Regex.Matches(source, lookfor, regexoptions);
var captured = found
                // linq-ify into list
                .Cast<Match>()
                // flatten to single list
                .SelectMany(o =>
                    // linq-ify
                    o.Groups.Cast<Capture>()
                        // don't need the pattern
                        .Skip(1)
                        // select what you wanted
                        .Select(c => c.Value));

这会将所有捕获的值"展平"到单个列表.要维护捕获组,请使用Select而不是SelectMany获取列表列表.

Answer 3

使用Linq的可能解决方案：

using System.Linq;
using System.Text.RegularExpressions;

static class Program {
    static void Main(string[] aargs) {
        string value = "I have a dog and a cat.";
        Regex regex = new Regex("dog|cat");
        var matchesList = (from Match m in regex.Matches(value) select m.Value).ToList();
    }
}