Binaryworld - ChildWindows - Get all the child windows of another window ... [ VB -> Windows ]

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

' The following variables are shared between the main ChildWindows procedure
' and the auxiliary (private) ChildWindows_CBK routine

' An array of Long holding the handle of all child windows.
Dim windows() As Long
' The number of elements in the array.
Dim windowsCount As Long

' Return an array of Long holding the handles of all the child windows
' of a given window. If hWnd = 0 it returns all the top-level windows.

Function ChildWindows(ByVal hWnd As Long) As Long()
  windowsCount = 0
  If hWnd Then
    EnumChildWindows hWnd, AddressOf EnumWindows_CBK, 1
  Else
    EnumWindows AddressOf EnumWindows_CBK, 1
  End If
  ' Trim uninitialized elements and return to caller.
  ReDim Preserve windows(windowsCount) As Long
  ChildWindows = windows()
End Function

' The callback routine, common to both EnumWindows and EnumChildWindows.

Private Function EnumWindows_CBK(ByVal hWnd As Long, ByVal lParam As Long) As _
  Long
  ' Make room in the array, if necessary.
  If windowsCount = 0 Then
    ReDim windows(100) As Long
  ElseIf windowsCount >= UBound(windows) Then
    ReDim Preserve windows(windowsCount + 100) As Long
  End If
  ' Store the new item.
  windowsCount = windowsCount + 1
  windows(windowsCount) = hWnd
  ' Return 1 to continue enumeration.
  EnumWindows_CBK = 1
End Function