Imports System.Runtime.InteropServices

Module Module1
  'System-Defined Device Interface Classes
  ' Device Interface Classes for Modem Devices
  Public Const GUID_DEVINTERFACE_MODEM As String = _
   "{2C7089AA-2E0E-11D1-B114-00C04FC2AAE4}"

  Private Const S_OK = 0

  Private Const INVALID_HANDLE_VALUE = -1
  Private Const ERROR_NO_MORE_ITEMS = 259

  'COM Fundamentals Functions
  Public Declare Unicode Function IIDFromString Lib "ole32.dll" _
   (ByVal lpsz As String, ByRef lpiid As Guid) As Integer

  'Device Installation Structures
  <StructLayout(LayoutKind.Sequential)>
  Public Structure SP_DEVINFO_DATA
    Dim cbSize As Integer
    Dim ClassGuid As Guid
    Dim DevInst As IntPtr
    Dim Reserved As IntPtr
  End Structure

  'Public Device Installation Functions

  Public Declare Function SetupDiDestroyDeviceInfoList Lib "setupapi.dll" _
   (ByVal DeviceInfoSet As IntPtr) As Boolean

  Public Declare Function SetupDiEnumDeviceInfo Lib "setupapi.dll" _
   (ByVal DeviceInfoSet As IntPtr, _
   ByVal MemberIndex As Integer, _
   ByRef DeviceInfoData As SP_DEVINFO_DATA) As Boolean

  'Flags - specifies control options that filter the device information elements that are added to the device information set
  Public Const DIGCF_PRESENT = &H2
  Public Const DIGCF_ALLCLASSES = &H4
  Public Const DIGCF_PROFILE = &H8
  Public Const DIGCF_DEVICEINTERFACE = &H10

  Public Declare Unicode Function SetupDiGetClassDevs _
   Lib "setupapi.dll" Alias "SetupDiGetClassDevsW" _
   (ByRef ClassGuid As Guid, _
   ByVal Enumerator As String, _
   ByVal hWndParent As IntPtr, _
   ByVal flags As Integer) As IntPtr

  Public Function RaiseAPIErrorByNumber(ByVal ErrNum As Integer) As String
    Return ErrNum.ToString & " (" & (New System.ComponentModel.Win32Exception(ErrNum)).Message & ")"
  End Function


  Public Sub GetModemsListFromClsid()
    Dim dwRes As Integer
    Dim m_ClassGUID As Guid
    Dim hDeviceInfoSet As IntPtr
    Dim bResult As Boolean
    Dim wIndex As Integer
    Dim m_DeviceInfoData As SP_DEVINFO_DATA

    'enum-ератор на основании GUID_DEVINTERFACE_MODEM
    'можно CLSIDFromString вместо IIDFromString -пофиг
    dwRes = IIDFromString(GUID_DEVINTERFACE_MODEM, m_ClassGUID)
    If dwRes <> S_OK Then
      Debug.Print("IIDFromString Error " & RaiseAPIErrorByNumber(dwRes))
      Exit Sub
    End If

    'DIGCF_DEVICEINTERFACE для этого m_ClassGUID -существенно!!!
    hDeviceInfoSet = SetupDiGetClassDevs(m_ClassGUID, vbNullString, 0, _
     DIGCF_PROFILE Or DIGCF_DEVICEINTERFACE) 'DIGCF_PRESENT Or
    If hDeviceInfoSet = INVALID_HANDLE_VALUE Then
      Debug.Print("SetupDiGetClassDevs Error " & RaiseAPIErrorByNumber(Err.LastDllError))
    Else
      Debug.Print("hDeviceInfoSet=" & hDeviceInfoSet.ToString)
      wIndex = 0
      m_DeviceInfoData.cbSize = Marshal.SizeOf(m_DeviceInfoData)
      Debug.Print("m_DeviceInfoData.cbSize=" & m_DeviceInfoData.cbSize)
      Do
        bResult = SetupDiEnumDeviceInfo(hDeviceInfoSet, wIndex, m_DeviceInfoData)
        If (bResult = False) And (Err.LastDllError = ERROR_NO_MORE_ITEMS) Then Exit Do
        If Err.LastDllError = 0 Then
          Debug.Print("wIndex=" & wIndex.ToString & " m_DeviceInfoData=" & m_DeviceInfoData.DevInst.ToString)
        Else
          Debug.Print("Err.LastDllError=" & RaiseAPIErrorByNumber(Err.LastDllError))
        End If
        wIndex = wIndex + 1
      Loop

      SetupDiDestroyDeviceInfoList(hDeviceInfoSet)
    End If

  End Sub

End Module

hDeviceInfoSet=12693760
m_DeviceInfoData.cbSize=28
wIndex=0 DevInst=1
wIndex=1 DevInst=2
wIndex=2 DevInst=3
wIndex=3 DevInst=4
wIndex=4 DevInst=5

hDeviceInfoSet=463398784
m_DeviceInfoData.cbSize=40
Err.LastDllError=1784 (Имеющийся буфер не подходит для указанной операции)
Err.LastDllError=1784 (Имеющийся буфер не подходит для указанной операции)
Err.LastDllError=1784 (Имеющийся буфер не подходит для указанной операции)
Err.LastDllError=1784 (Имеющийся буфер не подходит для указанной операции)
Err.LastDllError=1784 (Имеющийся буфер не подходит для указанной операции)

  Public Const GUID_DEVINTERFACE_MODEM As String = _
   "{2C7089AA-2E0E-11D1-B114-00C04FC2AAE4}"
  Public Const GUID_DEVINTERFACE_COMPORT As String = _
   "{86E0D1E0-8089-11D0-9CE4-08003E301F73}"
  Public Const GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR As String = _
   "{4D36E978-E325-11CE-BFC1-08002BE10318}"

  'Device Installation Structures
  <StructLayout(LayoutKind.Sequential)>
  Public Structure SP_DEVINFO_DATA
    Dim cbSize As Integer
    Dim ClassGuid As Guid
    Dim DevInst As IntPtr
    Dim Reserved As IntPtr
  End Structure

//С++
typedef struct _SP_DEVINFO_DATA {
  DWORD     cbSize;
  GUID      ClassGuid;
  DWORD     DevInst;
  ULONG_PTR Reserved;
} SP_DEVINFO_DATA, *PSP_DEVINFO_DATA;

  'Device Installation Structures
  <StructLayout(LayoutKind.Sequential)>
  Public Structure SP_DEVINFO_DATA
    Dim cbSize As Integer
    Dim ClassGuid As Guid
    Dim DevInst As Integer
    Dim Reserved As UIntPtr
  End Structure