如何获取文本文件C#中相同字符串的最后两个匹配项

using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
        // 读取文本文件内容
        string fileContent = File.ReadAllText("文件路径");

        // 使用正则表达式匹配字符串
        string pattern = "要匹配的字符串";
        MatchCollection matches = Regex.Matches(fileContent, pattern);

        // 获取最后两个匹配项
        List<string> lastTwoMatches = new List<string>();
        int matchCount = matches.Count;
        if (matchCount >= 2)
        {
            lastTwoMatches.Add(matches[matchCount - 2].Value);
            lastTwoMatches.Add(matches[matchCount - 1].Value);
        }
        else if (matchCount == 1)
        {
            lastTwoMatches.Add(matches[0].Value);
        }

        // 输出最后两个匹配项
        foreach (string match in lastTwoMatches)
        {
            Console.WriteLine(match);
        }
    }
}