获取文件夹ID c#
本文关键字：ID 文件夹 获取 | 更新日期: 2023-09-27 18:12:08
我试图跟踪一个文件和文件夹通过他们的生命周期(他们可能被移动或重命名)。我已经做了搜索，发现FileSystemWatcher可能是最流行的跟踪文件和文件夹的方法，然而，这对我来说不起作用，因为应用程序可能会也可能不会一直运行。我选择尝试通过ID来跟踪文件夹。
我已经找到了一种方法来跟踪文件从ID从答案到这个堆栈帖子。在这个答案中，我可以成功地根据方法B抓取文件id。
在搜索时，我发现了这个堆栈帖子，说明他找到了使用FSCTL_GET_OBJECT_ID的解决方案。我花了相当多的时间试图弄清楚如何使用这个功能，但我还是不明白。我基本上没有在c#中调用本机windows函数的经验。
谁能给我推一下正确的方向?我觉得我肯定错过了什么明显的东西。是否有c#不能访问文件/文件夹id的原因?跟踪文件/文件夹不常见吗?
编辑，添加代码: static uint returnVal;
//Working example to get File ID
public static string GetFileId(string path)
{
WinAPI.BY_HANDLE_FILE_INFORMATION objectFileInfo = new WinAPI.BY_HANDLE_FILE_INFORMATION();
FileInfo fi = new FileInfo(path);
FileStream fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
WinAPI.GetFileInformationByHandle(fs.Handle, out objectFileInfo);
fs.Close();
ulong fileIndex = ((ulong)objectFileInfo.FileIndexHigh << 32) + (ulong)objectFileInfo.FileIndexLow;
return fileIndex.ToString();
}
public static string GetFolderId(string path)
{
//Get a handle on the given folder
IntPtr cFile = WinAPI.CreateFile(
path,
WinAPI.GENERIC_READ,
FileShare.Read,
IntPtr.Zero,
(FileMode)WinAPI.OPEN_EXISTING,
WinAPI.FILE_FLAG_BACKUP_SEMANTICS,
IntPtr.Zero);
Console.WriteLine(path);
Console.WriteLine(cFile);
if ((int)cFile != -1)
{
int cFileSize = Marshal.SizeOf(typeof(IntPtr));
Console.WriteLine("cFile size = {0}", cFileSize);
IntPtr cFileBlob = Marshal.AllocHGlobal(cFileSize);
uint numBytesRead = 0;
WinAPI.DeviceIoControl(cFile, WinAPI.FSCTL_GET_OBJECT_ID, IntPtr.Zero, 0, cFileBlob, (uint)cFileSize, ref numBytesRead, IntPtr.Zero);
if (returnVal == 0)
{
Console.WriteLine(Marshal.GetLastWin32Error()); // Returning error 87 here
}
}
//Should be returning the ID from the folder.
return String.Empty;
}
public static void Main(string[] args)
{
Console.WriteLine(GetFileId(@"C:'Users'Matt'Desktop'TestDocument.txt"));
Console.WriteLine(GetFolderId(@"C:'Users'Matt'Desktop"));
}
}
class WinAPI
{
// Win32 constants for accessing files.
internal const int GENERIC_READ = unchecked((int)0x80000000);
internal const int FILE_FLAG_BACKUP_SEMANTICS = unchecked((int)0x02000000);
internal const int OPEN_EXISTING = unchecked((int)3);
internal const int FSCTL_GET_OBJECT_ID = 0x0009009c;
internal const int FSCTL_CREATE_OR_GET_OBJECT_ID = 0x000900c0;
[DllImport("kernel32.dll", SetLastError = true)]
public static extern bool DeviceIoControl(IntPtr hDevice, uint dwIoControlCode, IntPtr lpInBuffer, uint nInBufferSize, [Out] IntPtr lpOutBuffer, uint nOutBufferSize, ref uint lpBytesReturned, IntPtr lpOverlapped);
[DllImport("kernel32.dll", SetLastError = true)]
public static extern bool GetFileInformationByHandle(IntPtr hFile, out BY_HANDLE_FILE_INFORMATION lpFileInformation);
[DllImport("kernel32.dll", SetLastError = true)]
public static extern IntPtr CreateFile(
String fileName,
int dwDesiredAccess,
System.IO.FileShare dwShareMode,
IntPtr securityAttrs_MustBeZero,
System.IO.FileMode dwCreationDisposition,
int dwFlagsAndAttributes,
IntPtr hTemplateFile_MustBeZero);
public struct BY_HANDLE_FILE_INFORMATION
{
public uint FileAttributes;
public FILETIME CreationTime;
public FILETIME LastAccessTime;
public FILETIME LastWriteTime;
public uint VolumeSerialNumber;
public uint FileSizeHigh;
public uint FileSizeLow;
public uint NumberOfLinks;
public uint FileIndexHigh;
public uint FileIndexLow;
}
}
我从DeviceIoControl返回错误"87"，根据MSDN上的帖子，这是无效的参数(由于声誉限制，我无法发布更多链接)
看来你对FileSystemWatcher没有问题。所以，关于如何在c#中使用DeviceIoControl，看看这个答案:
物理磁盘大小不正确(IoCtlDiskGetDriveGeometry)
对于这个问题，使用以下代码完成:class Program {
const uint FSCTL_GET_OBJECT_ID=0x0009009c;
public static String GetFileId(String path) {
using(var fs=File.Open(
path,
FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite)
) {
WinAPI.BY_HANDLE_FILE_INFORMATION info;
WinAPI.GetFileInformationByHandle(fs.Handle, out info);
return String.Format(
"{0:x}", ((info.FileIndexHigh<<32)|info.FileIndexLow));
}
}
public static WinAPI.FILE_OBJECTID_BUFFER GetFolderIdBuffer(String path) {
using(var hFile=WinAPI.CreateFile(
path,
WinAPI.GENERIC_READ, FileShare.Read,
IntPtr.Zero,
(FileMode)WinAPI.OPEN_EXISTING,
WinAPI.FILE_FLAG_BACKUP_SEMANTICS,
IntPtr.Zero
)) {
if(null==hFile||hFile.IsInvalid)
throw new Win32Exception(Marshal.GetLastWin32Error());
var buffer=default(WinAPI.FILE_OBJECTID_BUFFER);
var nOutBufferSize=Marshal.SizeOf(buffer);
var lpOutBuffer=Marshal.AllocHGlobal(nOutBufferSize);
var lpBytesReturned=default(uint);
var result=
WinAPI.DeviceIoControl(
hFile, FSCTL_GET_OBJECT_ID,
IntPtr.Zero, 0,
lpOutBuffer, nOutBufferSize,
ref lpBytesReturned, IntPtr.Zero
);
if(!result)
throw new Win32Exception(Marshal.GetLastWin32Error());
var type=typeof(WinAPI.FILE_OBJECTID_BUFFER);
buffer=(WinAPI.FILE_OBJECTID_BUFFER)
Marshal.PtrToStructure(lpOutBuffer, type);
Marshal.FreeHGlobal(lpOutBuffer);
return buffer;
}
}
public static void Main(String[] args) {
Console.WriteLine(
GetFileId(@"C:'Users'Matt'Desktop'TestDocument.txt"));
var buffer=GetFolderIdBuffer(@"C:'Users'Matt'Desktop");
var objectId=buffer.ObjectId
.Reverse()
.Select(x => x.ToString("x2"))
.Aggregate(String.Concat);
Console.WriteLine("{0}", objectId);
}
}
class WinAPI {
internal const int
GENERIC_READ=unchecked((int)0x80000000),
FILE_FLAG_BACKUP_SEMANTICS=unchecked((int)0x02000000),
OPEN_EXISTING=unchecked((int)3);
[StructLayout(LayoutKind.Sequential)]
public struct FILE_OBJECTID_BUFFER {
public struct Union {
[MarshalAs(UnmanagedType.ByValArray, SizeConst=16)]
public byte[] BirthVolumeId;
[MarshalAs(UnmanagedType.ByValArray, SizeConst=16)]
public byte[] BirthObjectId;
[MarshalAs(UnmanagedType.ByValArray, SizeConst=16)]
public byte[] DomainId;
}
[MarshalAs(UnmanagedType.ByValArray, SizeConst=16)]
public byte[] ObjectId;
public Union BirthInfo;
[MarshalAs(UnmanagedType.ByValArray, SizeConst=48)]
public byte[] ExtendedInfo;
}
[StructLayout(LayoutKind.Sequential)]
public struct BY_HANDLE_FILE_INFORMATION {
public uint FileAttributes;
public FILETIME CreationTime;
public FILETIME LastAccessTime;
public FILETIME LastWriteTime;
public uint VolumeSerialNumber;
public uint FileSizeHigh;
public uint FileSizeLow;
public uint NumberOfLinks;
public uint FileIndexHigh;
public uint FileIndexLow;
}
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool DeviceIoControl(
SafeFileHandle hDevice,
uint dwIoControlCode,
IntPtr lpInBuffer,
uint nInBufferSize,
[Out] IntPtr lpOutBuffer,
int nOutBufferSize,
ref uint lpBytesReturned,
IntPtr lpOverlapped
);
[DllImport("kernel32.dll", SetLastError=true)]
public static extern SafeFileHandle CreateFile(
String fileName,
int dwDesiredAccess,
System.IO.FileShare dwShareMode,
IntPtr securityAttrs_MustBeZero,
System.IO.FileMode dwCreationDisposition,
int dwFlagsAndAttributes,
IntPtr hTemplateFile_MustBeZero
);
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool GetFileInformationByHandle(
IntPtr hFile, out BY_HANDLE_FILE_INFORMATION lpFileInformation);
}
使用
时需要命名空间using Microsoft.Win32.SafeHandles;