我正在用 .NET 编写目录扫描器。

对于每个文件/目录，我需要以下信息。

   class Info {
        public bool IsDirectory;
        public string Path;
        public DateTime ModifiedDate;
        public DateTime CreatedDate;
    }

我有这个功能:

      static List<Info> RecursiveMovieFolderScan(string path){

        var info = new List<Info>();
        var dirInfo = new DirectoryInfo(path);
        foreach (var dir in dirInfo.GetDirectories()) {
            info.Add(new Info() {
                IsDirectory = true,
                CreatedDate = dir.CreationTimeUtc,
                ModifiedDate = dir.LastWriteTimeUtc,
                Path = dir.FullName
            });

            info.AddRange(RecursiveMovieFolderScan(dir.FullName));
        }

        foreach (var file in dirInfo.GetFiles()) {
            info.Add(new Info()
            {
                IsDirectory = false,
                CreatedDate = file.CreationTimeUtc,
                ModifiedDate = file.LastWriteTimeUtc,
                Path = file.FullName
            });
        }

        return info; 
    }

事实证明这个实现非常慢。有什么办法可以加快速度吗？我正在考虑使用 FindFirstFileW 手动编码，但如果有更快的内置方式，我想避免这种情况。

最佳答案

这个实现需要一些调整，速度提高了 5-10 倍。

    static List<Info> RecursiveScan2(string directory) {
        IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
        WIN32_FIND_DATAW findData;
        IntPtr findHandle = INVALID_HANDLE_VALUE;

        var info = new List<Info>();
        try {
            findHandle = FindFirstFileW(directory + @"\*", out findData);
            if (findHandle != INVALID_HANDLE_VALUE) {

                do {
                    if (findData.cFileName == "." || findData.cFileName == "..") continue;

                    string fullpath = directory + (directory.EndsWith("\\") ? "" : "\\") + findData.cFileName;

                    bool isDir = false;

                    if ((findData.dwFileAttributes & FileAttributes.Directory) != 0) {
                        isDir = true;
                        info.AddRange(RecursiveScan2(fullpath));
                    }

                    info.Add(new Info()
                    {
                        CreatedDate = findData.ftCreationTime.ToDateTime(),
                        ModifiedDate = findData.ftLastWriteTime.ToDateTime(),
                        IsDirectory = isDir,
                        Path = fullpath
                    });
                }
                while (FindNextFile(findHandle, out findData));

            }
        } finally {
            if (findHandle != INVALID_HANDLE_VALUE) FindClose(findHandle);
        }
        return info;
    }

扩展方法:

 public static class FILETIMEExtensions {
        public static DateTime ToDateTime(this System.Runtime.InteropServices.ComTypes.FILETIME filetime ) {
            long highBits = filetime.dwHighDateTime;
            highBits = highBits << 32;
            return DateTime.FromFileTimeUtc(highBits + (long)filetime.dwLowDateTime);
        }
    }

互操作定义是:

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    public static extern IntPtr FindFirstFileW(string lpFileName, out WIN32_FIND_DATAW lpFindFileData);

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    public static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATAW lpFindFileData);

    [DllImport("kernel32.dll")]
    public static extern bool FindClose(IntPtr hFindFile);

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct WIN32_FIND_DATAW {
        public FileAttributes dwFileAttributes;
        internal System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
        internal System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
        internal System.Runtime.InteropServices.ComTypes.FILETIME ftLastWriteTime;
        public int nFileSizeHigh;
        public int nFileSizeLow;
        public int dwReserved0;
        public int dwReserved1;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public string cFileName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
        public string cAlternateFileName;
    }

关于c# - 在 .NET 中是否有更快的递归扫描目录的方法？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/724148/