这就是我们如何将文件作为其子目录的FileInfo，

var dir = new DirectoryInfo(rootPath);
FileInfo[] files = dir.GetFiles("*.*", SearchOption.AllDirectories);

下面是B. Clay Shannon的非静态excel文件代码:

class ExcelSearcher
{
    private List<string> _fileNames;

    public ExcelSearcher(List<string> filenames)
    {
        _fileNames = filenames;
    }
    public List<string> GetExcelFiles(string dir, List<string> filenames = null)
    {

        string dirName = dir;
        var dirNames = new List<string>();
        if (filenames != null)
        {
            _fileNames.Concat(filenames);
        }
        try
        {
            foreach (string f in Directory.GetFiles(dirName))
            {
                if (f.ToLower().EndsWith(".xls") || f.ToLower().EndsWith(".xlsx"))
                {
                    _fileNames.Add(f);
                }
            }
            dirNames = Directory.GetDirectories(dirName).ToList();
            foreach (string d in dirNames)
            {
                GetExcelFiles(d, _fileNames);
            }
        }
        catch (Exception ex)
        {
            //Bam
        }
        return _fileNames;
    }

一个简单干净的解决方案

/// <summary>
/// Scans a folder and all of its subfolders recursively, and updates the List of files
/// </summary>
/// <param name="sFullPath">Full path of the folder</param>
/// <param name="files">The list, where the output is expected</param>
internal static void EnumerateFiles(string sFullPath, List<FileInfo> fileInfoList)
{
    try
    {
        DirectoryInfo di = new DirectoryInfo(sFullPath);
        FileInfo[] files = di.GetFiles();

        foreach (FileInfo file in files)
            fileInfoList.Add(file);

        //Scan recursively
        DirectoryInfo[] dirs = di.GetDirectories();
        if (dirs == null || dirs.Length < 1)
            return;
        foreach (DirectoryInfo dir in dirs)
            EnumerateFiles(dir.FullName, fileInfoList);

    }
    catch (Exception ex)
    {
        Logger.Write("Exception in Helper.EnumerateFiles", ex);
    }
}

IEnumerable<string> GetFilesFromDir(string dir) =>
 Directory.EnumerateFiles(dir).Concat(
 Directory.EnumerateDirectories(dir)
          .SelectMany(subdir => GetFilesFromDir(subdir)));

最短的记录

string[] files = Directory.GetFiles(@"your_path", "*.jpg", SearchOption.AllDirectories);

var d = new DirectoryInfo(@"C:\logs");
var list = d.GetFiles("*.txt").Select(m => m.Name).ToList();