Search
Module:
Directory

   Desktop Functions:

   Smart Device Functions:


Show Recent Changes
Subscribe (RSS)
Misc. Pages
Comments
FAQ
Helpful Tools
Playground
Suggested Reading
Website TODO List
Download Visual Studio Add-In

GetVolumeInformation (kernel32)
 
.
Summary

C++ Signature:

    TCHAR volumeName[MAX_PATH + 1] = { 0 };
    TCHAR fileSystemName[MAX_PATH + 1] = { 0 };
    DWORD serialNumber = 0;
    DWORD maxComponentLen = 0;
    DWORD fileSystemFlags = 0;
    if (GetVolumeInformation(
        _T("C:\\"),
        volumeName,
        ARRAYSIZE(volumeName),
        &serialNumber,
        &maxComponentLen,
        &fileSystemFlags,
        fileSystemName,
        ARRAYSIZE(fileSystemName)))
    {
        m_sn_textbox.Format(_T("GetVolumeInformation : %lu"),serialNumber);
    }

C# Signature:

  [DllImport("Kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
  [return: MarshalAs(UnmanagedType.Bool)]
  public extern static bool GetVolumeInformation(
    string rootPathName,
    StringBuilder volumeNameBuffer,
    int volumeNameSize,
    out uint volumeSerialNumber,
    out uint maximumComponentLength,
    out FileSystemFeature fileSystemFlags,
    out FileSystemFlags fileSystemFlags,
    StringBuilder fileSystemNameBuffer,
    int nFileSystemNameSize);

VB Signature:

  Private Declare Auto Function GetVolumeInformation Lib "kernel32.dll" ( _
     ByVal RootPathName As String, _
     ByVal VolumeNameBuffer As System.Text.StringBuilder, _
     ByVal VolumeNameSize As UInt32, _
     ByRef VolumeSerialNumber As UInt32, _
     ByRef MaximumComponentLength As UInt32, _
     ByRef FileSystemFlags As UInt32, _
     ByVal FileSystemNameBuffer As System.Text.StringBuilder, _
     ByVal FileSystemNameSize As UInt32) As UInt32

User-Defined Types:

  [Flags]
  public enum FileSystemFeature : uint {
    /// <summary>
    /// The file system preserves the case of file names when it places a name on disk.
    /// </summary>
    CasePreservedNames = 2,

    /// <summary>
    /// The file system supports case-sensitive file names.
    /// </summary>
    CaseSensitiveSearch = 1,

    /// <summary>
    /// The specified volume is a direct access (DAX) volume. This flag was introduced in Windows 10, version 1607.
    /// </summary>
    DaxVolume = 0x20000000,

    /// <summary>
    /// The file system supports file-based compression.
    /// </summary>
    FileCompression = 0x10,

    /// <summary>
    /// The file system supports named streams.
    /// </summary>
    NamedStreams = 0x40000,

    /// <summary>
    /// The file system preserves and enforces access control lists (ACL).
    /// </summary>
    PersistentACLS = 8,

    /// <summary>
    /// The specified volume is read-only.
    /// </summary>
    ReadOnlyVolume = 0x80000,

    /// <summary>
    /// The volume supports a single sequential write.
    /// </summary>
    SequentialWriteOnce = 0x100000,

    /// <summary>
    /// The file system supports the Encrypted File System (EFS).
    /// </summary>
    SupportsEncryption = 0x20000,

    /// <summary>
    /// The specified volume supports extended attributes. An extended attribute is a piece of
    /// application-specific metadata that an application can associate with a file and is not part
    /// of the file's data.
    /// </summary>
    SupportsExtendedAttributes = 0x00800000,

    /// <summary>
    /// The specified volume supports hard links. For more information, see Hard Links and Junctions.
    /// </summary>
    SupportsHardLinks = 0x00400000,

    /// <summary>
    /// The file system supports object identifiers.
    /// </summary>
    SupportsObjectIDs = 0x10000,

    /// <summary>
    /// The file system supports open by FileID. For more information, see FILE_ID_BOTH_DIR_INFO.
    /// </summary>
    SupportsOpenByFileId = 0x01000000,

    /// <summary>
    /// The file system supports re-parse points.
    /// </summary>
    SupportsReparsePoints = 0x80,

    /// <summary>
    /// The file system supports sparse files.
    /// </summary>
    SupportsSparseFiles = 0x40,

    /// <summary>
    /// The volume supports transactions.
    /// </summary>
    SupportsTransactions = 0x200000,

    /// <summary>
    /// The specified volume supports update sequence number (USN) journals. For more information,
    /// see Change Journal Records.
    /// </summary>
    SupportsUsnJournal = 0x02000000,

    /// <summary>
    /// The file system supports Unicode in file names as they appear on disk.
    /// </summary>
    UnicodeOnDisk = 4,

    /// <summary>
    /// The specified volume is a compressed volume, for example, a DoubleSpace volume.
    /// </summary>
    VolumeIsCompressed = 0x8000,

    /// <summary>
    /// The file system supports disk quotas.
    /// </summary>
    VolumeQuotas = 0x20
  }

}

Notes:

The volumeSerialNumber is not optional with this signature!!!

Tips & Tricks:

If you specify rootPathName as a drive letter (eg not a volume name) then you have to terminate it with a backslash.

Sample Code:

StringBuilder volname = new StringBuilder(261);
StringBuilder fsname = new StringBuilder(261);
uint sernum, maxlen;
FileSystemFeature flags;
if(!GetVolumeInformation("c:\\", volname, volname.Capacity, out sernum, out maxlen, out flags, fsname, fsname.Capacity))
    Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
string volnamestr = volname.ToString();
string fsnamestr = fsname.ToString();

Sample code - VB.NET:

   ''' <summary>
   ''' Returns volume name and serial number, maximum path component length, and filesystem name and flags
   ''' for the specified directory. Works with UNC. Can throw an exception.
   ''' </summary>
   ''' <param name="FolderPath">Path to drive or shared folder to find about.</param>
   ''' <param name="VolumeName">Returns volume name.</param>
   ''' <param name="VolumeSerialNumber">Returns volume serial number.</param>
   ''' <param name="MaxComponentLength">Returns max. path component lenght.</param>
   ''' <param name="FileSystemFlags">Returns file system flags - see http://msdn.microsoft.com/en-us/library/aa364993(VS.85).aspx</param>
   ''' <param name="FileSystemName">Returns file system name.</param>
   ''' <remarks></remarks>
   Public Sub GetVolumeInfo( _
     ByVal FolderPath As String, _
     ByRef VolumeName As String, _
     ByRef VolumeSerialNumber As String, _
     ByRef MaxComponentLength As UInt32, _
     ByRef FileSystemFlags As UInt32, _
     ByRef FileSystemName As String)
      ' see http://msdn.microsoft.com/en-us/library/aa364993(VS.85).aspx
      Dim sRootFolder As String = IO.Path.GetPathRoot(FolderPath)
      If Not sRootFolder.EndsWith("\") Then sRootFolder &= "\"
      Const MAX_PATH As Integer = &H104
      Dim volname As New System.Text.StringBuilder(MAX_PATH + 1)
      Dim fsname As New System.Text.StringBuilder(MAX_PATH + 1)
      Dim sernum As UInt32
      Dim RetVal As UInt32 = GetVolumeInformation(sRootFolder, volname, volname.Capacity, _
                          sernum, MaxComponentLength, FileSystemFlags, _
                          fsname, fsname.Capacity)
      If RetVal = 0 Then Throw New System.ComponentModel.Win32Exception(Err.LastDllError)
      VolumeName = volname.ToString
      FileSystemName = fsname.ToString

      Dim hpart, lpart As Integer
      hpart = sernum \ 65536
      lpart = sernum - hpart * 65536L
      VolumeSerialNumber = Hex(hpart).PadLeft(4, "0"c) & "-" & Hex(lpart).PadLeft(4, "0"c)
   End Sub

Alternative Managed API:

System.Management.ManagementObject("Win32_LogicalDisk.DeviceID=" & DriveLetter & ":")

Sample:

Private Function GetVolumeSerial(ByVal DriveLetter As String) As String

    'Check for valid drive letter argument.
    Dim ValidDriveLetters As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    If ValidDriveLetters.IndexOf(DriveLetter) <> -1 Then
    If DriveLetter.Length = 1 Then
        Dim Disk As New System.Management.ManagementObject("Win32_LogicalDisk.DeviceID=""" & DriveLetter & ":""")
        Dim DiskProperty As System.Management.PropertyData
        For Each DiskProperty In Disk.Properties
        If DiskProperty.Name = "VolumeSerialNumber" Then
            Return DiskProperty.Value.ToString  '.ToString 'Return the volume serial number.
        End If
        Next DiskProperty
    End If
    End If
    Return Nothing 'Invalid drive letter.

End Function

Do you know one? Please contribute it!

Documentation

Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

 
Access PInvoke.net directly from VS:
Terms of Use
Edit This Page
Find References
Show Printable Version
Revisions