自2018年4月以来，Windows 10能够获取或设置是否使用fsutil.exe将目录标记为区分大小写。
有没有一种方法可以通过编程方式查询目录的区分大小写，而无需运行fsutil.exe或通过使用不同大小写的格式伪造文件来查看它们是否冲突？
我还没有真正找到通过研究测试这一点的方法。我读过这是一个实际的NTFS属性，但在获取文件属性时却没有显示。我还注意到，如果存在两个不同的大小写，FindFirstFile将返回正确文件的大小写。除此之外，我不知道要去哪里，因为实际上没有很多信息。这些东西仍然很新。
正如其他人所提到的，由于可比性问题，区分大小写在Windows中不是一个好主意。我意识到了这一点，我的目标是扫描文件系统中现有的区分大小写的目录并使用它。
进度：
我发现Windows的FindFirstFile和friends函数即使不使用FIND_FIRST_EX_CASE_SENSITIVE也尊重目录的区分大小写。它不会返回带有无效大小写的文件。现在，我试图找出是否有一个很好的方法可以利用这一点。
答案 0 :(得分：3)
在@eryksun的评论帮助下，这是我的P / Invoke解决方案。
编辑2：添加了SetDirectoryCaseSensitive()
编辑3：添加了IsDirectoryCaseSensitivitySupported()
我已经在使用NtQueryInformationFile FileCaseSensitiveInformation来读取FILE_INFORMATION_CLASS结构的同时实现了本地方法FILE_CASE_SENSITIVE_INFORMATION。
public static partial class NativeMethods {
public static readonly IntPtr INVALID_HANDLE = new IntPtr(-1);
public const FileAttributes FILE_FLAG_BACKUP_SEMANTICS = (FileAttributes) 0x02000000;
public enum NTSTATUS : uint {
SUCCESS = 0x00000000,
NOT_IMPLEMENTED = 0xC0000002,
INVALID_INFO_CLASS = 0xC0000003,
INVALID_PARAMETER = 0xC000000D,
NOT_SUPPORTED = 0xC00000BB,
DIRECTORY_NOT_EMPTY = 0xC0000101,
}
public enum FILE_INFORMATION_CLASS {
None = 0,
// Note: If you use the actual enum in here, remember to
// start the first field at 1. There is nothing at zero.
FileCaseSensitiveInformation = 71,
}
// It's called Flags in FileCaseSensitiveInformation so treat it as flags
[Flags]
public enum CASE_SENSITIVITY_FLAGS : uint {
CaseInsensitiveDirectory = 0x00000000,
CaseSensitiveDirectory = 0x00000001,
}
[StructLayout(LayoutKind.Sequential)]
public struct IO_STATUS_BLOCK {
[MarshalAs(UnmanagedType.U4)]
public NTSTATUS Status;
public ulong Information;
}
[StructLayout(LayoutKind.Sequential)]
public struct FILE_CASE_SENSITIVE_INFORMATION {
[MarshalAs(UnmanagedType.U4)]
public CASE_SENSITIVITY_FLAGS Flags;
}
// An override, specifically made for FileCaseSensitiveInformation, no IntPtr necessary.
[DllImport("ntdll.dll")]
[return: MarshalAs(UnmanagedType.U4)]
public static extern NTSTATUS NtQueryInformationFile(
IntPtr FileHandle,
ref IO_STATUS_BLOCK IoStatusBlock,
ref FILE_CASE_SENSITIVE_INFORMATION FileInformation,
int Length,
FILE_INFORMATION_CLASS FileInformationClass);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern IntPtr CreateFile(
[MarshalAs(UnmanagedType.LPTStr)] string filename,
[MarshalAs(UnmanagedType.U4)] FileAccess access,
[MarshalAs(UnmanagedType.U4)] FileShare share,
IntPtr securityAttributes, // optional SECURITY_ATTRIBUTES struct or IntPtr.Zero
[MarshalAs(UnmanagedType.U4)] FileMode creationDisposition,
[MarshalAs(UnmanagedType.U4)] FileAttributes flagsAndAttributes,
IntPtr templateFile);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool CloseHandle(
IntPtr hObject);
public static bool IsDirectoryCaseSensitive(string directory, bool throwOnError = true) {
// Read access is NOT required
IntPtr hFile = CreateFile(directory, 0, FileShare.ReadWrite,
IntPtr.Zero, FileMode.Open,
FILE_FLAG_BACKUP_SEMANTICS, IntPtr.Zero);
if (hFile == INVALID_HANDLE)
throw new Win32Exception();
try {
IO_STATUS_BLOCK iosb = new IO_STATUS_BLOCK();
FILE_CASE_SENSITIVE_INFORMATION caseSensitive = new FILE_CASE_SENSITIVE_INFORMATION();
NTSTATUS status = NtQueryInformationFile(hFile, ref iosb, ref caseSensitive,
Marshal.SizeOf<FILE_CASE_SENSITIVE_INFORMATION>(),
FILE_INFORMATION_CLASS.FileCaseSensitiveInformation);
switch (status) {
case NTSTATUS.SUCCESS:
return caseSensitive.Flags.HasFlag(CASE_SENSITIVITY_FLAGS.CaseSensitiveDirectory);
case NTSTATUS.NOT_IMPLEMENTED:
case NTSTATUS.NOT_SUPPORTED:
case NTSTATUS.INVALID_INFO_CLASS:
case NTSTATUS.INVALID_PARAMETER:
// Not supported, must be older version of windows.
// Directory case sensitivity is impossible.
return false;
default:
throw new Exception($"Unknown NTSTATUS: {(uint)status:X8}!");
}
}
finally {
CloseHandle(hFile);
}
}
}
这里是通过实现NTSetInformationFile来设置目录区分大小写的实现。 （其中的参数列表与NTQueryInformationFile相同。同样，由于@eryksun的见识，该问题得以解决。
FILE_WRITE_ATTRIBUTES是未在C＃中实现的FileAccess标志，因此需要从值0x100进行定义和/或强制转换。
partial class NativeMethods {
public const FileAccess FILE_WRITE_ATTRIBUTES = (FileAccess) 0x00000100;
// An override, specifically made for FileCaseSensitiveInformation, no IntPtr necessary.
[DllImport("ntdll.dll")]
[return: MarshalAs(UnmanagedType.U4)]
public static extern NTSTATUS NtSetInformationFile(
IntPtr FileHandle,
ref IO_STATUS_BLOCK IoStatusBlock,
ref FILE_CASE_SENSITIVE_INFORMATION FileInformation,
int Length,
FILE_INFORMATION_CLASS FileInformationClass);
// Require's elevated priviledges
public static void SetDirectoryCaseSensitive(string directory, bool enable) {
// FILE_WRITE_ATTRIBUTES access is the only requirement
IntPtr hFile = CreateFile(directory, FILE_WRITE_ATTRIBUTES, FileShare.ReadWrite,
IntPtr.Zero, FileMode.Open,
FILE_FLAG_BACKUP_SEMANTICS, IntPtr.Zero);
if (hFile == INVALID_HANDLE)
throw new Win32Exception();
try {
IO_STATUS_BLOCK iosb = new IO_STATUS_BLOCK();
FILE_CASE_SENSITIVE_INFORMATION caseSensitive = new FILE_CASE_SENSITIVE_INFORMATION();
if (enable)
caseSensitive.Flags |= CASE_SENSITIVITY_FLAGS.CaseSensitiveDirectory;
NTSTATUS status = NtSetInformationFile(hFile, ref iosb, ref caseSensitive,
Marshal.SizeOf<FILE_CASE_SENSITIVE_INFORMATION>(),
FILE_INFORMATION_CLASS.FileCaseSensitiveInformation);
switch (status) {
case NTSTATUS.SUCCESS:
return;
case NTSTATUS.DIRECTORY_NOT_EMPTY:
throw new IOException($"Directory \"{directory}\" contains matching " +
$"case-insensitive files!");
case NTSTATUS.NOT_IMPLEMENTED:
case NTSTATUS.NOT_SUPPORTED:
case NTSTATUS.INVALID_INFO_CLASS:
case NTSTATUS.INVALID_PARAMETER:
// Not supported, must be older version of windows.
// Directory case sensitivity is impossible.
throw new NotSupportedException("This version of Windows does not support directory case sensitivity!");
default:
throw new Exception($"Unknown NTSTATUS: {(uint)status:X8}!");
}
}
finally {
CloseHandle(hFile);
}
}
}
最后，如果Windows版本支持区分大小写的目录，我添加了一种计算一次的方法。这样只会在Temp中创建一个名称为GUID的文件夹，并检查NTSTATUS的结果（因此它可以检查它知道可以访问的文件夹）。
partial class NativeMethods {
// Use the same directory so it does not need to be recreated when restarting the program
private static readonly string TempDirectory =
Path.Combine(Path.GetTempPath(), "88DEB13C-E516-46C3-97CA-46A8D0DDD8B2");
private static bool? isSupported;
public static bool IsDirectoryCaseSensitivitySupported() {
if (isSupported.HasValue)
return isSupported.Value;
// Make sure the directory exists
if (!Directory.Exists(TempDirectory))
Directory.CreateDirectory(TempDirectory);
IntPtr hFile = CreateFile(TempDirectory, 0, FileShare.ReadWrite,
IntPtr.Zero, FileMode.Open,
FILE_FLAG_BACKUP_SEMANTICS, IntPtr.Zero);
if (hFile == INVALID_HANDLE)
throw new Exception("Failed to open file while checking case sensitivity support!");
try {
IO_STATUS_BLOCK iosb = new IO_STATUS_BLOCK();
FILE_CASE_SENSITIVE_INFORMATION caseSensitive = new FILE_CASE_SENSITIVE_INFORMATION();
// Strangely enough, this doesn't fail on files
NTSTATUS result = NtQueryInformationFile(hFile, ref iosb, ref caseSensitive,
Marshal.SizeOf<FILE_CASE_SENSITIVE_INFORMATION>(),
FILE_INFORMATION_CLASS.FileCaseSensitiveInformation);
switch (result) {
case NTSTATUS.SUCCESS:
return (isSupported = true).Value;
case NTSTATUS.NOT_IMPLEMENTED:
case NTSTATUS.INVALID_INFO_CLASS:
case NTSTATUS.INVALID_PARAMETER:
case NTSTATUS.NOT_SUPPORTED:
// Not supported, must be older version of windows.
// Directory case sensitivity is impossible.
return (isSupported = false).Value;
default:
throw new Exception($"Unknown NTSTATUS {(uint)result:X8} while checking case sensitivity support!");
}
}
finally {
CloseHandle(hFile);
try {
// CHOOSE: If you delete the folder, future calls to this will not be any faster
// Directory.Delete(TempDirectory);
}
catch { }
}
}
}