Option Explicit

Public Declare Function EnumWindows Lib "user32" (ByVal _
      lpEnumFunc As Long, ByVal lParam As Long) As Long

Public Declare Function EnumChildWindows Lib "user32" ( _
      ByVal hWndParent As Long, ByVal lpEnumFunc As Long, _
      ByVal lParam As Long) As Long

Private Declare Function GetClassName Lib "user32" Alias _
      "GetClassNameA" (ByVal hwnd As Long, ByVal lpClassName _
      As String, ByVal nMaxCount As Long) As Long

Private Declare Function GetWindowTextLength Lib "user32" _
      Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long

Private Declare Function GetWindowText Lib "user32" Alias _
      "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString _
      As String, ByVal cch As Long) As Long

Private Declare Function GetParent Lib "user32" (ByVal hwnd _
      As Long) As Long

Public Declare Function IsWindowVisible Lib "user32" (ByVal _
      hwnd As Long) As Long

Private Declare Function GetWindowLong Lib "user32" Alias _
      "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex _
      As Long) As Long

Private Const GWL_HWNDPARENT = (-8)
Private Const GWL_STYLE = (-16)

Private Const WS_VISIBLE = &H10000000
Private Const WS_BORDER = &H800000

Public Function EnumWinProc(ByVal hwnd As Long, ByVal lParam _
      As Long) As Long
  If (IsWindowVisible(hwnd) Or lParam) Then
    If GetParent(hwnd) = 0 Then
      If GetWindowLong(hwnd, GWL_HWNDPARENT) = 0 Then
        AddWndInfosToListView hwnd, lParam, _
              frmEnumWindows.lvwTopLevelWnd
      End If
    End If
  End If

  EnumWinProc = True
End Function

Public Function EnumChildProc(ByVal hwnd As Long, ByVal lParam _
      As Long) As Long
  Dim nStyle As Long

  Select Case lParam
    Case 0
      nStyle = GetWindowLong(hwnd, GWL_STYLE)
      nStyle = nStyle And (WS_VISIBLE Or WS_BORDER)
      If (nStyle = (WS_VISIBLE Or WS_BORDER)) Then
        AddWndInfosToListView hwnd, lParam, _
              frmEnumWindows.lvwChildWnd
      End If

    Case 1
      lParam = 0
      AddWndInfosToListView hwnd, lParam, _
            frmEnumWindows.lvwChildWnd

    Case 2
      AddWndInfosToListView hwnd, lParam, _
            frmEnumWindows.lvwChildWnd

    Case Else
  End Select

  EnumChildProc = True
End Function

Private Sub AddWndInfosToListView(ByVal hwnd As Long, ByVal _
      lParam As Long, ByVal lvw As ListView)

  Dim nRetVal       As Long
  Dim strClassName  As String
  Dim strWndTitle   As String

  Dim itmX          As ListItem

  strClassName = Space$(64)
  nRetVal = GetClassName(hwnd, strClassName, Len(strClassName))
  strClassName = Left$(strClassName, nRetVal)

  nRetVal = GetWindowTextLength(hwnd)
  If nRetVal > 0 Then
    If nRetVal > 256 Then nRetVal = 255
    strWndTitle = Space$(nRetVal + 1)
    GetWindowText hwnd, strWndTitle, Len(strWndTitle)
    strWndTitle = Left$(strWndTitle, nRetVal)
  End If

  If Len(strWndTitle) > 0 Or lParam <> 0 Then
    Set itmX = lvw.ListItems.Add(Text:=strWndTitle, _
          Key:=CStr(hwnd) & "h")
    itmX.SubItems(1) = CStr(hwnd)
    itmX.SubItems(2) = strClassName
  End If
End Sub