How to detect appearance of MDI scrollbars.

I'm using VB5 Professional Edition. I don't know how to detect the appearance of
scrollbars event in an MDI form when two or more child forms are displayed with
their margins extending otside the MDI borders. Is it possible to detect such an event
or does one have to work with the the ScaleLeft and ScaleTop properties?
flavourAsked:
Who is Participating?
 
mtoftConnect With a Mentor Commented:
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long

Private Type SCROLLINFO
    cbSize As Long
    fMask As Long
    nMin As Long
    nMax As Long
    nPage As Long
    nPos As Long
    nTrackPos As Long
End Type

' Scroll Info Mask Flags
Private Const SIF_RANGE = &H1
Private Const SIF_PAGE = &H2
Private Const SIF_POS = &H4
Private Const SIF_DISABLENOSCROLL = &H8
Private Const SIF_TRACKPOS = &H10
Private Const SIF_ALL = SIF_RANGE Or SIF_PAGE Or SIF_POS Or SIF_TRACKPOS

' Scroll Bar Constants
Private Const SB_HORZ = 0
Private Const SB_VERT = 1
Private Const SB_CTL = 2
Private Const SB_BOTH = 3

Private Declare Function GetScrollInfo Lib "user32" (ByVal hWnd As Long, ByVal n As Long, lpScrollInfo As SCROLLINFO) As Long

Private Sub MDIForm_Click()
    Debug.Print "Horz: " & IsScrollBarVisible(Me, SB_HORZ)
    Debug.Print "Vert: " & IsScrollBarVisible(Me, SB_VERT)
End Sub

Function IsScrollBarVisible(ByVal TheForm As MDIForm, ByVal Scrollbar As Long)
    ' Find the MDIClient area
    Dim lHwnd As Long
    lHwnd = FindWindowEx(TheForm.hWnd, 0&, "MDIClient", vbNullString)
       
    If lHwnd = 0 Then
        MsgBox "Could not find MDI Client window.", vbExclamation
        Exit Function
    End If
       
    ' Get scrollbar information for MDIClient window
    Dim lpInfo As SCROLLINFO
    lpInfo.cbSize = LenB(lpInfo)
    lpInfo.fMask = SIF_ALL
    If GetScrollInfo(lHwnd, Scrollbar, lpInfo) = 0 Then
        ' Scrollbars are not visible
        IsScrollBarVisible = False
    Else
        ' We got some information about the scrollbars
        ' scrollbars are visible...
        ' Information available in lpInfo
        IsScrollBarVisible = (lpInfo.nPage - 1) <> lpInfo.nMax
    End If
End Function

0
 
flavourAuthor Commented:
Thank you very much for the help I'll try it strait away!
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.