Question

我需要从文件中提取特定序列的200个文件，并将结果写入新的csv文件中。我只是在学习C＃，但在过去有很多其他语言的经验。我已经尝试查找所有单独的步骤，以及我不明白的正则表达，但我不知道如何将它们拼接在一起。示例文本：

- ＆GT; SAT1_988_Connection_Verify


EA0683010A01030F15A40202004E2000

E0068300

E40683010278053A


＆GT;

（S45,10：38：35 AM）

算法步骤

 1) I need to point the program at a directory with the files.
 2) I need the program to search through each file in the directory.
 3) I need to find the lines that starts with "E40", of which there could be multiple or none.  Additionally, this line varies in length.
 4) I need to grab that line, as well as the two before it, which are highlighted in the nested block quote above.
 5) There is always a blank line after the target line.
 6)I need to write those three lines separated by commas in a text document.

到目前为止我的代码：

using System;
using System.Collections.Generic;
using System.IO;

namespace ConsoleApplication2
{
class Program
{
    static void Main()
    {
        string path = @"C:\ETT\Test.txt";
        string[] readText = File.ReadAllLines(path);
        foreach (string s in readText)
        {

        }
    }
  public static string getBetween(string[] strSource, string strKey)
    {
        int Start, End;
      if (strSource.Contains(strKey))
      {
          Start = Array.IndexOf(strSource, strKey) -2;
          End = Array.IndexOf(strSource, strKey) + 1;
          return strSource.Substring(Start, End - Start);
      }
      else
      {
          return "";
      }
    }
}
}