如何处理名称超过259个字符的文件？

我正在研究一个应用程序，它遍历某些目录中的每个文件，并对这些文件执行一些操作。 其中，我必须检索文件的大小和文件修改的date。

某些文件全名（目录+文件名）太长，我无法使用.NET Framework FileInfo ，它仅限于MAX_PATH （260个字符）。 许多Web源build议通过P / Invoke使用本机Win32函数来访问名称太长的文件。

目前，Win32函数似乎也出现了完全相同的问题。 例如， GetFileAttributesEx （kernel32.dll）失败，Win32错误3 ERROR_PATH_NOT_FOUND为270个字节的path。

同样的文件可以成功地从记事本2打开，并成功地显示在Windows资源pipe理器（但Visual Studio 2010例如由于259个字符的限制¹没有打开它）。

如果文件path长度为270个字符，我能做些什么来访问文件？

笔记：

  • 删除或忽略文件path长度超过259个字符的文件不是解决scheme。

  • 我只在寻找兼容Unicode的解决scheme。

  • 该应用程序将在安装了.NET Framework 4的Windows 2008 / Vista或更高版本下运行。

¹令人惊讶的是，Microsoft Word 2007失败了，抱怨说没有任何软盘的计算机上的“软盘太小”，或者剩下4GB的RAM时，“RAM内存不足” “杀毒软件需要更新”。 他们是否会停留一天，至less在诸如Microsoft Office这样的关键产品中显示这样愚蠢的毫无意义的错误？

.NET 4.6.2解决scheme

按照此处所述使用\\?\C:\Verrrrrrrrrrrry long path语法。

.NET核心解决scheme

这只是因为框架为你添加了长path语法。

Pre .NET 4.6.2解决scheme

使用P / Invoke的长path语法和Win32 API函数的Unicode版本。 从命名文件，path和命名空间 ：

Windows API有许多function，也有Unicode版本允许扩展长度path的最大总path长度为32,767个字符。 此类path由用反斜杠分隔的组件组成，每个组件由GetVolumeInformation函数的lpMaximumComponentLength参数（此值通常为255个字符）中返回的值组成。 要指定扩展长度path，请使用\\?\前缀。 比如\\?\D:\very long path 。

阅读此Microsoft支持页面可能也很有趣。

Kim Hamilton在“Long Paths in .NET”中对BCL Team博客中的一个非常广泛的解释列举了一些处理这些path的方法，他声称这是直接在.NET中不支持这种语法的原因：

有几个原因，我们不愿意在过去增加漫长的道路，为什么我们仍然很小心… …。

\\?\前缀不仅可以启用长path， 它会导致path被传递到文件系统，只需通过Windows API进行最less的修改。 结果是\\?\closuresWindows API执行的文件名规范化，包括删除尾随空格，扩展'。' 和“..”，将相对path转换为完整path，等等

具有\\?\前缀的长path可用于大多数与文件相关的 Windows API，但不是所有的Windows API。 例如，如果文件名比MAX_PATH长，LoadLibrary <…>会失败。 在整个Windows API中都有类似的例子。 一些解决方法存在，但他们是在个案的基础上。

另一个因素是与其他基于Windows的应用程序和Windowsshell本身的兼容性

由于这个问题越来越普遍，微软正在努力解决这个问题。 事实上，作为一个及时的Vista插件，你会注意到一些改变，减less了MAX_PATH限制的机会：许多特殊的文件夹名称缩短了，更有趣的是，shell使用自动path缩小function试图把它们挤成260个字符。

警告：您可能需要直接调用Windows API，因为我认为.NET Framework可能不支持这种path语法。

您可以尝试Delimon库，它是Microsoft TechNet上基于.NET Framework 4的库，用于克服长文件名问题：

Delimon.Win32.I O Library（V4.0）。

它有自己的版本从System.IO的关键方法。 例如，你可以replace： 

 System.IO.Directory.GetFiles

同 

 Delimon.Win32.IO.Directory.GetFiles

这将让你处理长文件和文件夹。

从网站：

Delimon.Win32.IOreplace了System.IO的基本文件function，并支持最多32,767个字符的文件和文件夹名称。

此库是在.NET Framework 4.0上编写的，可以在x86和x64系统上使用。 标准System.IO名称空间的文件和文件夹限制可以处理文件名为260个字符，文件夹名称为240个字符（MAX_PATH通常configuration为260个字符）的文件。 通常，您会遇到System.IO.PathTooLongException错误与标准.NET库。

.NET Core现在支持长path名，而不需要扩展语法 。

我创build了我自己的LongFile和LongDirectory类来解决这个问题。 我通常会使用System.IO.File时使用它。

有可能会有优化等，但它已经好几年了。 

 public static class LongFile { private const int MAX_PATH = 260; public static bool Exists(string path) { if (path.Length < MAX_PATH) return System.IO.File.Exists(path); var attr = NativeMethods.GetFileAttributesW(GetWin32LongPath(path)); return (attr != NativeMethods.INVALID_FILE_ATTRIBUTES && ((attr & NativeMethods.FILE_ATTRIBUTE_ARCHIVE) == NativeMethods.FILE_ATTRIBUTE_ARCHIVE)); } public static void Delete(string path) { if (path.Length < MAX_PATH) System.IO.File.Delete(path); else { bool ok = NativeMethods.DeleteFileW(GetWin32LongPath(path)); if (!ok) ThrowWin32Exception(); } } public static void AppendAllText(string path, string contents) { AppendAllText(path, contents, Encoding.Default); } public static void AppendAllText(string path, string contents, Encoding encoding) { if (path.Length < MAX_PATH) { System.IO.File.AppendAllText(path, contents, encoding); } else { var fileHandle = CreateFileForAppend(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Write)) { var bytes = encoding.GetBytes(contents); fs.Position = fs.Length; fs.Write(bytes, 0, bytes.Length); } } } public static void WriteAllText(string path, string contents) { WriteAllText(path, contents, Encoding.Default); } public static void WriteAllText(string path, string contents, Encoding encoding) { if (path.Length < MAX_PATH) { System.IO.File.WriteAllText(path, contents, encoding); } else { var fileHandle = CreateFileForWrite(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Write)) { var bytes = encoding.GetBytes(contents); fs.Write(bytes, 0, bytes.Length); } } } public static void WriteAllBytes(string path, byte[] bytes) { if (path.Length < MAX_PATH) { System.IO.File.WriteAllBytes(path, bytes); } else { var fileHandle = CreateFileForWrite(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Write)) { fs.Write(bytes, 0, bytes.Length); } } } public static void Copy(string sourceFileName, string destFileName) { Copy(sourceFileName, destFileName, false); } public static void Copy(string sourceFileName, string destFileName, bool overwrite) { if (sourceFileName.Length < MAX_PATH && (destFileName.Length < MAX_PATH)) System.IO.File.Copy(sourceFileName, destFileName, overwrite); else { var ok = NativeMethods.CopyFileW(GetWin32LongPath(sourceFileName), GetWin32LongPath(destFileName), !overwrite); if (!ok) ThrowWin32Exception(); } } public static void Move(string sourceFileName, string destFileName) { if (sourceFileName.Length < MAX_PATH && (destFileName.Length < MAX_PATH)) System.IO.File.Move(sourceFileName, destFileName); else { var ok = NativeMethods.MoveFileW(GetWin32LongPath(sourceFileName), GetWin32LongPath(destFileName)); if (!ok) ThrowWin32Exception(); } } public static string ReadAllText(string path) { return ReadAllText(path, Encoding.Default); } public static string ReadAllText(string path, Encoding encoding) { if (path.Length < MAX_PATH) { return System.IO.File.ReadAllText(path, encoding); } var fileHandle = GetFileHandle(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Read)) { var data = new byte[fs.Length]; fs.Read(data, 0, data.Length); return encoding.GetString(data); } } public static string[] ReadAllLines(string path) { return ReadAllLines(path, Encoding.Default); } public static string[] ReadAllLines(string path, Encoding encoding) { if (path.Length < MAX_PATH) { return System.IO.File.ReadAllLines(path, encoding); } var fileHandle = GetFileHandle(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Read)) { var data = new byte[fs.Length]; fs.Read(data, 0, data.Length); var str = encoding.GetString(data); if (str.Contains("\r")) return str.Split(new[] { "\r\n" }, StringSplitOptions.None); return str.Split('\n'); } } public static byte[] ReadAllBytes(string path) { if (path.Length < MAX_PATH) return System.IO.File.ReadAllBytes(path); var fileHandle = GetFileHandle(GetWin32LongPath(path)); using (var fs = new System.IO.FileStream(fileHandle, System.IO.FileAccess.Read)) { var data = new byte[fs.Length]; fs.Read(data, 0, data.Length); return data; } } public static void SetAttributes(string path, FileAttributes attributes) { if (path.Length < MAX_PATH) { System.IO.File.SetAttributes(path, attributes); } else { var longFilename = GetWin32LongPath(path); NativeMethods.SetFileAttributesW(longFilename, (int)attributes); } } #region Helper methods private static SafeFileHandle CreateFileForWrite(string filename) { if (filename.Length >= MAX_PATH) filename = GetWin32LongPath(filename); SafeFileHandle hfile = NativeMethods.CreateFile(filename, (int)NativeMethods.FILE_GENERIC_WRITE, NativeMethods.FILE_SHARE_NONE, IntPtr.Zero, NativeMethods.CREATE_ALWAYS, 0, IntPtr.Zero); if (hfile.IsInvalid) ThrowWin32Exception(); return hfile; } private static SafeFileHandle CreateFileForAppend(string filename) { if (filename.Length >= MAX_PATH) filename = GetWin32LongPath(filename); SafeFileHandle hfile = NativeMethods.CreateFile(filename, (int)NativeMethods.FILE_GENERIC_WRITE, NativeMethods.FILE_SHARE_NONE, IntPtr.Zero, NativeMethods.CREATE_NEW, 0, IntPtr.Zero); if (hfile.IsInvalid) { hfile = NativeMethods.CreateFile(filename, (int)NativeMethods.FILE_GENERIC_WRITE, NativeMethods.FILE_SHARE_NONE, IntPtr.Zero, NativeMethods.OPEN_EXISTING, 0, IntPtr.Zero); if (hfile.IsInvalid) ThrowWin32Exception(); } return hfile; } internal static SafeFileHandle GetFileHandle(string filename) { if (filename.Length >= MAX_PATH) filename = GetWin32LongPath(filename); SafeFileHandle hfile = NativeMethods.CreateFile(filename, (int)NativeMethods.FILE_GENERIC_READ, NativeMethods.FILE_SHARE_READ, IntPtr.Zero, NativeMethods.OPEN_EXISTING, 0, IntPtr.Zero); if (hfile.IsInvalid) ThrowWin32Exception(); return hfile; } internal static SafeFileHandle GetFileHandleWithWrite(string filename) { if (filename.Length >= MAX_PATH) filename = GetWin32LongPath(filename); SafeFileHandle hfile = NativeMethods.CreateFile(filename, (int)(NativeMethods.FILE_GENERIC_READ | NativeMethods.FILE_GENERIC_WRITE | NativeMethods.FILE_WRITE_ATTRIBUTES), NativeMethods.FILE_SHARE_NONE, IntPtr.Zero, NativeMethods.OPEN_EXISTING, 0, IntPtr.Zero); if (hfile.IsInvalid) ThrowWin32Exception(); return hfile; } public static System.IO.FileStream GetFileStream(string filename, FileAccess access = FileAccess.Read) { var longFilename = GetWin32LongPath(filename); SafeFileHandle hfile; if (access == FileAccess.Write) { hfile = NativeMethods.CreateFile(longFilename, (int)(NativeMethods.FILE_GENERIC_READ | NativeMethods.FILE_GENERIC_WRITE | NativeMethods.FILE_WRITE_ATTRIBUTES), NativeMethods.FILE_SHARE_NONE, IntPtr.Zero, NativeMethods.OPEN_EXISTING, 0, IntPtr.Zero); } else { hfile = NativeMethods.CreateFile(longFilename, (int)NativeMethods.FILE_GENERIC_READ, NativeMethods.FILE_SHARE_READ, IntPtr.Zero, NativeMethods.OPEN_EXISTING, 0, IntPtr.Zero); } if (hfile.IsInvalid) ThrowWin32Exception(); return new System.IO.FileStream(hfile, access); } [DebuggerStepThrough] public static void ThrowWin32Exception() { int code = Marshal.GetLastWin32Error(); if (code != 0) { throw new System.ComponentModel.Win32Exception(code); } } public static string GetWin32LongPath(string path) { if (path.StartsWith(@"\\?\")) return path; if (path.StartsWith("\\")) { path = @"\\?\UNC\" + path.Substring(2); } else if (path.Contains(":")) { path = @"\\?\" + path; } else { var currdir = Environment.CurrentDirectory; path = Combine(currdir, path); while (path.Contains("\\.\\")) path = path.Replace("\\.\\", "\\"); path = @"\\?\" + path; } return path.TrimEnd('.'); ; } private static string Combine(string path1, string path2) { return path1.TrimEnd('\\') + "\\" + path2.TrimStart('\\').TrimEnd('.'); ; } #endregion public static void SetCreationTime(string path, DateTime creationTime) { long cTime = 0; long aTime = 0; long wTime = 0; using (var handle = GetFileHandleWithWrite(path)) { NativeMethods.GetFileTime(handle, ref cTime, ref aTime, ref wTime); var fileTime = creationTime.ToFileTimeUtc(); if (!NativeMethods.SetFileTime(handle, ref fileTime, ref aTime, ref wTime)) { throw new Win32Exception(); } } } public static void SetLastAccessTime(string path, DateTime lastAccessTime) { long cTime = 0; long aTime = 0; long wTime = 0; using (var handle = GetFileHandleWithWrite(path)) { NativeMethods.GetFileTime(handle, ref cTime, ref aTime, ref wTime); var fileTime = lastAccessTime.ToFileTimeUtc(); if (!NativeMethods.SetFileTime(handle, ref cTime, ref fileTime, ref wTime)) { throw new Win32Exception(); } } } public static void SetLastWriteTime(string path, DateTime lastWriteTime) { long cTime = 0; long aTime = 0; long wTime = 0; using (var handle = GetFileHandleWithWrite(path)) { NativeMethods.GetFileTime(handle, ref cTime, ref aTime, ref wTime); var fileTime = lastWriteTime.ToFileTimeUtc(); if (!NativeMethods.SetFileTime(handle, ref cTime, ref aTime, ref fileTime)) { throw new Win32Exception(); } } } public static DateTime GetLastWriteTime(string path) { long cTime = 0; long aTime = 0; long wTime = 0; using (var handle = GetFileHandleWithWrite(path)) { NativeMethods.GetFileTime(handle, ref cTime, ref aTime, ref wTime); return DateTime.FromFileTimeUtc(wTime); } } }

和一个对应的LongDirectory ： 

 public class LongDirectory { private const int MAX_PATH = 260; public static void CreateDirectory(string path) { if (string.IsNullOrWhiteSpace(path)) return; if (path.Length < MAX_PATH) { System.IO.Directory.CreateDirectory(path); } else { var paths = GetAllPathsFromPath(GetWin32LongPath(path)); foreach (var item in paths) { if (!LongExists(item)) { var ok = NativeMethods.CreateDirectory(item, IntPtr.Zero); if (!ok) { ThrowWin32Exception(); } } } } } public static void Delete(string path) { Delete(path, false); } public static void Delete(string path, bool recursive) { if (path.Length < MAX_PATH && !recursive) { System.IO.Directory.Delete(path, false); } else { if (!recursive) { bool ok = NativeMethods.RemoveDirectory(GetWin32LongPath(path)); if (!ok) ThrowWin32Exception(); } else { DeleteDirectories(new string[] { GetWin32LongPath(path) }); } } } private static void DeleteDirectories(string[] directories) { foreach (string directory in directories) { string[] files = LongDirectory.GetFiles(directory, null, System.IO.SearchOption.TopDirectoryOnly); foreach (string file in files) { LongFile.Delete(file); } directories = LongDirectory.GetDirectories(directory, null, System.IO.SearchOption.TopDirectoryOnly); DeleteDirectories(directories); bool ok = NativeMethods.RemoveDirectory(GetWin32LongPath(directory)); if (!ok) ThrowWin32Exception(); } } public static bool Exists(string path) { if (path.Length < MAX_PATH) return System.IO.Directory.Exists(path); return LongExists(GetWin32LongPath(path)); } private static bool LongExists(string path) { var attr = NativeMethods.GetFileAttributesW(path); return (attr != NativeMethods.INVALID_FILE_ATTRIBUTES && ((attr & NativeMethods.FILE_ATTRIBUTE_DIRECTORY) == NativeMethods.FILE_ATTRIBUTE_DIRECTORY)); } public static string[] GetDirectories(string path) { return GetDirectories(path, null, SearchOption.TopDirectoryOnly); } public static string[] GetDirectories(string path, string searchPattern) { return GetDirectories(path, searchPattern, SearchOption.TopDirectoryOnly); } public static string[] GetDirectories(string path, string searchPattern, System.IO.SearchOption searchOption) { searchPattern = searchPattern ?? "*"; var dirs = new List<string>(); InternalGetDirectories(path, searchPattern, searchOption, ref dirs); return dirs.ToArray(); } private static void InternalGetDirectories(string path, string searchPattern, System.IO.SearchOption searchOption, ref List<string> dirs) { NativeMethods.WIN32_FIND_DATA findData; IntPtr findHandle = NativeMethods.FindFirstFile(System.IO.Path.Combine(GetWin32LongPath(path), searchPattern), out findData); try { if (findHandle != new IntPtr(-1)) { do { if ((findData.dwFileAttributes & System.IO.FileAttributes.Directory) != 0) { if (findData.cFileName != "." && findData.cFileName != "..") { string subdirectory = System.IO.Path.Combine(path, findData.cFileName); dirs.Add(GetCleanPath(subdirectory)); if (searchOption == SearchOption.AllDirectories) { InternalGetDirectories(subdirectory, searchPattern, searchOption, ref dirs); } } } } while (NativeMethods.FindNextFile(findHandle, out findData)); NativeMethods.FindClose(findHandle); } else { ThrowWin32Exception(); } } catch (Exception) { NativeMethods.FindClose(findHandle); throw; } } public static string[] GetFiles(string path) { return GetFiles(path, null, SearchOption.TopDirectoryOnly); } public static string[] GetFiles(string path, string searchPattern) { return GetFiles(path, searchPattern, SearchOption.TopDirectoryOnly); } public static string[] GetFiles(string path, string searchPattern, System.IO.SearchOption searchOption) { searchPattern = searchPattern ?? "*"; var files = new List<string>(); var dirs = new List<string> { path }; if (searchOption == SearchOption.AllDirectories) { //Add all the subpaths dirs.AddRange(LongDirectory.GetDirectories(path, null, SearchOption.AllDirectories)); } foreach (var dir in dirs) { NativeMethods.WIN32_FIND_DATA findData; IntPtr findHandle = NativeMethods.FindFirstFile(System.IO.Path.Combine(GetWin32LongPath(dir), searchPattern), out findData); try { if (findHandle != new IntPtr(-1)) { do { if ((findData.dwFileAttributes & System.IO.FileAttributes.Directory) == 0) { string filename = System.IO.Path.Combine(dir, findData.cFileName); files.Add(GetCleanPath(filename)); } } while (NativeMethods.FindNextFile(findHandle, out findData)); NativeMethods.FindClose(findHandle); } } catch (Exception) { NativeMethods.FindClose(findHandle); throw; } } return files.ToArray(); } public static void Move(string sourceDirName, string destDirName) { if (sourceDirName.Length < MAX_PATH || destDirName.Length < MAX_PATH) { System.IO.Directory.Move(sourceDirName, destDirName); } else { var ok = NativeMethods.MoveFileW(GetWin32LongPath(sourceDirName), GetWin32LongPath(destDirName)); if (!ok) ThrowWin32Exception(); } } #region Helper methods [DebuggerStepThrough] public static void ThrowWin32Exception() { int code = Marshal.GetLastWin32Error(); if (code != 0) { throw new System.ComponentModel.Win32Exception(code); } } public static string GetWin32LongPath(string path) { if (path.StartsWith(@"\\?\")) return path; var newpath = path; if (newpath.StartsWith("\\")) { newpath = @"\\?\UNC\" + newpath.Substring(2); } else if (newpath.Contains(":")) { newpath = @"\\?\" + newpath; } else { var currdir = Environment.CurrentDirectory; newpath = Combine(currdir, newpath); while (newpath.Contains("\\.\\")) newpath = newpath.Replace("\\.\\", "\\"); newpath = @"\\?\" + newpath; } return newpath.TrimEnd('.'); } private static string GetCleanPath(string path) { if (path.StartsWith(@"\\?\UNC\")) return @"\\" + path.Substring(8); if (path.StartsWith(@"\\?\")) return path.Substring(4); return path; } private static List<string> GetAllPathsFromPath(string path) { bool unc = false; var prefix = @"\\?\"; if (path.StartsWith(prefix + @"UNC\")) { prefix += @"UNC\"; unc = true; } var split = path.Split('\\'); int i = unc ? 6 : 4; var list = new List<string>(); var txt = ""; for (int a = 0; a < i; a++) { if (a > 0) txt += "\\"; txt += split[a]; } for (; i < split.Length; i++) { txt = Combine(txt, split[i]); list.Add(txt); } return list; } private static string Combine(string path1, string path2) { return path1.TrimEnd('\\') + "\\" + path2.TrimStart('\\').TrimEnd('.'); } #endregion }

NativeMethods ： 

 internal static class NativeMethods { internal const int FILE_ATTRIBUTE_ARCHIVE = 0x20; internal const int INVALID_FILE_ATTRIBUTES = -1; internal const int FILE_READ_DATA = 0x0001; internal const int FILE_WRITE_DATA = 0x0002; internal const int FILE_APPEND_DATA = 0x0004; internal const int FILE_READ_EA = 0x0008; internal const int FILE_WRITE_EA = 0x0010; internal const int FILE_READ_ATTRIBUTES = 0x0080; internal const int FILE_WRITE_ATTRIBUTES = 0x0100; internal const int FILE_SHARE_NONE = 0x00000000; internal const int FILE_SHARE_READ = 0x00000001; internal const int FILE_ATTRIBUTE_DIRECTORY = 0x10; internal const long FILE_GENERIC_WRITE = STANDARD_RIGHTS_WRITE | FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA | FILE_APPEND_DATA | SYNCHRONIZE; internal const long FILE_GENERIC_READ = STANDARD_RIGHTS_READ | FILE_READ_DATA | FILE_READ_ATTRIBUTES | FILE_READ_EA | SYNCHRONIZE; internal const long READ_CONTROL = 0x00020000L; internal const long STANDARD_RIGHTS_READ = READ_CONTROL; internal const long STANDARD_RIGHTS_WRITE = READ_CONTROL; internal const long SYNCHRONIZE = 0x00100000L; internal const int CREATE_NEW = 1; internal const int CREATE_ALWAYS = 2; internal const int OPEN_EXISTING = 3; internal const int MAX_PATH = 260; internal const int MAX_ALTERNATE = 14; [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] internal struct WIN32_FIND_DATA { public System.IO.FileAttributes dwFileAttributes; public FILETIME ftCreationTime; public FILETIME ftLastAccessTime; public FILETIME ftLastWriteTime; public uint nFileSizeHigh; //changed all to uint, otherwise you run into unexpected overflow public uint nFileSizeLow; //| public uint dwReserved0; //| public uint dwReserved1; //v [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)] public string cFileName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_ALTERNATE)] public string cAlternate; } [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern SafeFileHandle CreateFile(string lpFileName, int dwDesiredAccess, int dwShareMode, IntPtr lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, IntPtr hTemplateFile); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool CopyFileW(string lpExistingFileName, string lpNewFileName, bool bFailIfExists); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern int GetFileAttributesW(string lpFileName); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool DeleteFileW(string lpFileName); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool MoveFileW(string lpExistingFileName, string lpNewFileName); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool SetFileTime(SafeFileHandle hFile, ref long lpCreationTime, ref long lpLastAccessTime, ref long lpLastWriteTime); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool GetFileTime(SafeFileHandle hFile, ref long lpCreationTime, ref long lpLastAccessTime, ref long lpLastWriteTime); [DllImport("kernel32", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData); [DllImport("kernel32", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA lpFindFileData); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool FindClose(IntPtr hFindFile); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool RemoveDirectory(string path); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern bool CreateDirectory(string lpPathName, IntPtr lpSecurityAttributes); [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)] internal static extern int SetFileAttributesW(string lpFileName, int fileAttributes); }

我遇到了一个这样的问题，我正在写一个应用程序。 当我接近达到260个字符的限制时，我会将一个networking驱动器dynamic映射到完整path的某个段，从而显着减less完整path+文件名的长度。 这不是一个很好的解决scheme，但它完成了工作。

GetFileAttributesEx的MSDN参考说：

在该函数的ANSI版本中，名称被限制为MAX_PATH个字符。 要将此限制扩展为32,767个宽字符，请调用该函数的Unicode版本，并将“\\？\”添加到path中。 有关更多信息，请参阅命名文件 。

所以你想要使用GetFileAttributesExW并以“\\？\”为前缀

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