C# Signature:

[DllImport("Kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
extern static bool GetVolumeInformation(
  string RootPathName,
  StringBuilder VolumeNameBuffer,
  int VolumeNameSize,
  out uint VolumeSerialNumber,
  out uint MaximumComponentLength,
  out uint 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:

None.

Notes:

The VolumeSerialNumber is not optional with this signature!!!

Tips & Tricks:

If you specify RootPathName as a driveletter (eg not a volume name) then you have to terminate it with a backslash.

I had to change the return type to int and compare with 0. The bool return value didn't work for me.

Adding the attribute [return: MarshalAs(UnmanagedType.Bool)] should make the bool return value work.

Sample Code:

StringBuilder volname = new StringBuilder(261);
StringBuilder fsname = new StringBuilder(261);
uint sernum, maxlen, 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!

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).