string path="指定路径";

	string filename =“需要查找的文件名.csv";

	List<string> lineStringList = new List<string>();//存储所有读取到的文件

	DirectoryInfo[] dateDirArr = new DirectoryInfo(path).GetDirectories(); //取指定路径下的所有目录

	foreach (DirectoryInfo directoryInfo in dateDirArr)

	{

	string fullName = filePath + directoryInfo.Name + "\\" + filename;

	if (!File.Exists(fullName))

	{

	continue;//目录下不存在此文件，返回。

	}

	FileInfo file = new FileInfo(fullName);

	StreamReader reader = new StreamReader(file.FullName);

	while (!reader.EndOfStream)//判断是否读取完成

	{

	lineStringList.Add(reader.ReadLine());

	}

	reader.Close();

	}