本文介绍了如何使用主文件表数据读取文件属性的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

在我的项目中,我想列出特定文件路径下的所有文件.对某些用户权限的问题是使用主文件表来访问所有文件.

In my project i want list out all files under a specific file path.Do to some user permission issue am using master file table to access all files.

使用此线程我可以读取特定文件位置下的所有文件

Using this thread I can able to read all files under a specific file location

这将列出文件名和父FRN,是否也可以列出文件属性????

This one will list the file name and parent FRN,is there any way to list the file attributes also????

我也想显示这些细节.

  1. 创建日期
  2. 修改后的数据
  3. 文件大小

USN_RECORD包含这些详细信息.

USN_RECORD contains these details.

推荐答案

public IEnumerable<FileDetails> EnumerateFiles(string szDriveLetter)
        {

            List<FileDetails> fdList = new List<FileDetails>();
            try
            {
                var usnRecord = default(USN_RECORD);
                var mft = default(MFT_ENUM_DATA);
                var dwRetBytes = 0;
                int cb;
                var dicFrnLookup = new Dictionary<long, FSNode>();
                bool bIsFile;

                // This shouldn't be called more than once.
                if (m_Buffer.ToInt32() != 0)
                {
                    throw new Exception("invalid buffer");
                }

                // Assign buffer size
                m_BufferSize = 65536;
                //64KB

                // Allocate a buffer to use for reading records.
                m_Buffer = Marshal.AllocHGlobal(m_BufferSize);

                // correct path
                szDriveLetter = szDriveLetter.TrimEnd('\\');

                // Open the volume handle
                m_hCJ = OpenVolume(szDriveLetter);
                uint iny = NativeMethods.GetLastError();
                // Check if the volume handle is valid.
                if (m_hCJ == INVALID_HANDLE_VALUE)
                {
                    throw new Exception("Couldn't open handle to the volume.");
                }

                mft.StartFileReferenceNumber = 0;
                mft.LowUsn = 0;
                mft.HighUsn = long.MaxValue;

                do
                {
                    if (DeviceIoControl(m_hCJ, FSCTL_ENUM_USN_DATA, ref mft, Marshal.SizeOf(mft), m_Buffer, m_BufferSize, ref dwRetBytes, IntPtr.Zero))
                    {
                        cb = dwRetBytes;
                        // Pointer to the first record
                        IntPtr pUsnRecord = new IntPtr(m_Buffer.ToInt32() + 8);

                        while ((dwRetBytes > 8))
                        {
                            // Copy pointer to USN_RECORD structure.
                            usnRecord = (USN_RECORD)Marshal.PtrToStructure(pUsnRecord, usnRecord.GetType());

                            // The filename within the USN_RECORD.
                            string fileName = Marshal.PtrToStringUni(new IntPtr(pUsnRecord.ToInt32() + usnRecord.FileNameOffset), usnRecord.FileNameLength / 2);

                            bIsFile = !usnRecord.FileAttribute.HasFlag(FileAttributes.Directory);
                            dicFrnLookup.Add(usnRecord.FileReferenceNumber, new FSNode(usnRecord.ParentFileReferenceNumber, fileName, bIsFile));

                            // Pointer to the next record in the buffer.
                            pUsnRecord = new IntPtr(pUsnRecord.ToInt32() + usnRecord.RecordLength);

                            dwRetBytes -= usnRecord.RecordLength;
                        }

                        // The first 8 bytes is always the start of the next USN.
                        mft.StartFileReferenceNumber = Marshal.ReadInt64(m_Buffer, 0);


                    }
                    else
                    {
                        break; // TODO: might not be correct. Was : Exit Do

                    }

                } while (!(cb <= 8));

                // Resolve all paths for Files
                foreach (FSNode oFSNode in dicFrnLookup.Values.Where(o => o.IsFile))
                {
                    FileDetails fd = new FileDetails();
                    string sFullPath = oFSNode.FileName;
                    FSNode oParentFSNode = oFSNode;

                    while (dicFrnLookup.TryGetValue(oParentFSNode.ParentFRN, out oParentFSNode))
                    {
                        sFullPath = string.Concat(oParentFSNode.FileName, "\\", sFullPath);
                    }
                    sFullPath = string.Concat(szDriveLetter, "\\", sFullPath);

                    //File Attribute details
                    WIN32_FILE_ATTRIBUTE_DATA data;

                    if (NativeMethods.GetFileAttributesEx(@sFullPath, GET_FILEEX_INFO_LEVELS.GetFileExInfoStandard, out data))
                    {

                        fd.FileSize = Convert.ToDouble(data.fileSizeLow);
                    }

                    long highBits = data.creationTime.dwHighDateTime;
                    highBits = highBits << 32;

                    DateTime createdDate = DateTime.FromFileTimeUtc(highBits + (uint)data.creationTime.dwLowDateTime);
                    fd.CreatedDate = createdDate.ToString(CultureInfo.CurrentCulture);
                    fd.CreatedYear = createdDate.Year;
                    fd.FileType = data.filetype;

                    long highBitsModified = data.lastWriteTime.dwHighDateTime;
                    highBitsModified = highBitsModified << 32;
                    DateTime modifiedDate = DateTime.FromFileTimeUtc(highBitsModified + (uint)data.creationTime.dwLowDateTime);
                    fd.ModifiedYear = modifiedDate.Year;
                    fd.ModifiedDate = modifiedDate.ToString(CultureInfo.CurrentCulture);
                    fd.FilePath = sFullPath;
                    fd.MachineName = SystemInformation.ComputerName;

                    List<string> names = sFullPath.Split('.').ToList();
                    fd.FileType = "." + names.LastOrDefault();

                    List<string> folders = sFullPath.Split('\\').ToList();
                    //fd.FileName = folders.LastOrDefault();
                    fd.FileName = oFSNode.FileName;
                    fdList.Add(fd);

                    yield return fd;
                }
            }
            finally
            {
                //// cleanup
                Cleanup();
            }
        }

public class NativeMethods
        {
            [DllImport("KERNEL32.dll", CharSet = CharSet.None)]
            public static extern bool GetFileAttributesEx(string path, GET_FILEEX_INFO_LEVELS level, out WIN32_FILE_ATTRIBUTE_DATA data);

            [DllImport("kernel32.dll")]
            public static extern uint GetLastError();

        }

这篇关于如何使用主文件表数据读取文件属性的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

06-03 22:01
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