如何使用 .NET 读取和修改 NTFS 备用数据流？

使用 .NET 读取和修改 NTFS 备用数据流

NTFS 备用数据流 (ADS) 是与常规文件关联的隐藏数据流新技术文件系统 (NTFS)。这些流可用于存储附加信息，例如用户评论、版本历史或多媒体内容，而不影响主文件数据。

阅读 ADS

至要读取 ADS，可以使用 CreateFileW 函数，并将 dwDesiredAccess 参数设置为 GENERIC_WRITE。这将打开流以进行读取和写入。然后，您可以使用 ReadFile 函数读取流的内容。

修改 ADS

要修改 ADS，您可以使用 CreateFileW 函数，并将 dwDesiredAccess 参数设置为GENERIC_WRITE。这将打开流以进行读取和写入。然后，您可以使用 WriteFile 函数将新内容写入流。

以下是如何读取和修改 ADS 的 C# 示例：

using System.Runtime.InteropServices;

class Program
{
    static void Main(string[] args)
    {
        // Open the main file stream
        var mainStream = NativeMethods.CreateFileW(
            "testfile",
            NativeConstants.GENERIC_WRITE,
            NativeConstants.FILE_SHARE_WRITE,
            IntPtr.Zero,
            NativeConstants.OPEN_ALWAYS,
            0,
            IntPtr.Zero);

        // Open the ADS stream
        var stream = NativeMethods.CreateFileW(
            "testfile:stream",
            NativeConstants.GENERIC_WRITE,
            NativeConstants.FILE_SHARE_WRITE,
            IntPtr.Zero,
            NativeConstants.OPEN_ALWAYS,
            0,
            IntPtr.Zero);

        // Write data to the ADS stream
        var data = "Hello world!";
        NativeMethods.WriteFile(stream, data, data.Length, out var bytesWritten, IntPtr.Zero);

        // Close the ADS stream
        NativeMethods.CloseHandle(stream);

        // Close the main file stream
        NativeMethods.CloseHandle(mainStream);
    }
}

public partial class NativeMethods
{

    /// Return Type: HANDLE->void*
    ///lpFileName: LPCWSTR->WCHAR*
    ///dwDesiredAccess: DWORD->unsigned int
    ///dwShareMode: DWORD->unsigned int
    ///lpSecurityAttributes: LPSECURITY_ATTRIBUTES->_SECURITY_ATTRIBUTES*
    ///dwCreationDisposition: DWORD->unsigned int
    ///dwFlagsAndAttributes: DWORD->unsigned int
    ///hTemplateFile: HANDLE->void*
    [DllImportAttribute("kernel32.dll", EntryPoint = "CreateFileW")]
    public static extern System.IntPtr CreateFileW(
        [InAttribute()] [MarshalAsAttribute(UnmanagedType.LPWStr)] string lpFileName, 
        uint dwDesiredAccess, 
        uint dwShareMode, 
        [InAttribute()] System.IntPtr lpSecurityAttributes, 
        uint dwCreationDisposition, 
        uint dwFlagsAndAttributes, 
        [InAttribute()] System.IntPtr hTemplateFile
    );

    /// Return Type: BOOL->int
    ///hFile: HANDLE->void*
    ///lpBuffer: LPVOID->void*
    ///nNumberOfBytesToWrite: DWORD->unsigned int
    ///lpNumberOfBytesWritten: LPDWORD->DWORD*
    ///lpOverlapped: LPOVERLAPPED->_OVERLAPPED*
    [DllImportAttribute("kernel32.dll", EntryPoint = "WriteFile")]
    public static extern int WriteFile(
        System.IntPtr hFile, 
        [InAttribute()] System.IntPtr lpBuffer, 
        uint nNumberOfBytesToWrite, 
        out uint lpNumberOfBytesWritten, 
        [InAttribute()] System.IntPtr lpOverlapped
    );

    /// Return Type: BOOL->int
    ///hObject: HANDLE->void*
    [DllImportAttribute("kernel32.dll", EntryPoint = "CloseHandle")]
    public static extern int CloseHandle(
        [InAttribute()] System.IntPtr hObject
    );

}


public partial class NativeConstants
{

    /// GENERIC_WRITE -> (0x40000000L)
    public const int GENERIC_WRITE = 1073741824;

    /// FILE_SHARE_DELETE -> 0x00000004
    public const int FILE_SHARE_DELETE = 4;

    /// FILE_SHARE_WRITE -> 0x00000002
    public const int FILE_SHARE_WRITE = 2;

    /// FILE_SHARE_READ -> 0x00000001
    public const int FILE_SHARE_READ = 1;

    /// OPEN_ALWAYS -> 4
    public const int OPEN_ALWAYS = 4;
}

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