C# Definition:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
struct USB_ROOT_HUB_NAME
{
   public int ActualLength;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst = BUFFER_SIZE)]
   public string RootHubName;
}

VB Definition:

Structure USB_ROOT_HUB_NAME
   Public TODO
End Structure

User-Defined Field Types:

None.

Notes:

typedef struct _USB_ROOT_HUB_NAME {
   ULONG  ActualLength;
   WCHAR  RootHubName[1];
} USB_ROOT_HUB_NAME, *PUSB_ROOT_HUB_NAME;

Example:

// Open a handle to the Host Controller
IntPtr h = CreateFile(ControllerDevicePath, GENERIC_WRITE, FILE_SHARE_WRITE, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
if (h.ToInt32() != INVALID_HANDLE_VALUE)
{
   int nBytesReturned;
   USB_ROOT_HUB_NAME HubName = new USB_ROOT_HUB_NAME();
   int nBytes = Marshal.SizeOf(HubName);
   IntPtr ptrHubName = Marshal.AllocHGlobal(nBytes);

   // get the Hub Name
   if (DeviceIoControl(h, IOCTL_USB_GET_ROOT_HUB_NAME, ptrHubName, nBytes, ptrHubName, nBytes, out nBytesReturned, IntPtr.Zero))
   {
     HubName = (USB_ROOT_HUB_NAME)Marshal.PtrToStructure(ptrHubName, typeof(USB_ROOT_HUB_NAME));
     string HubDevicePath = @"\\.\" + HubName.RootHubName;
   }
   Marshal.FreeHGlobal(ptrHubName);
   CloseHandle(h);
}