Scrolling using Window's Messages / Win32 API

[hymced]

Hi all,

I have recently attempted to use the DetectScroll method developed by CPearson: http://www.cpearson.com/excel/DetectScroll.htm

It no longer works because it is based on the "WM_VSCROLL" messages, which I cannot find in any window's message stream using Spy++.

From this observation, I tried scrolling with Window's Messages and Window's API functions only

Let's assume we have these handles:

mainHwnd = Application.hWnd
dskHwnd = FindWindowEx(mainHwnd, 0, "XLDESK", vbNullString)
wbkHwnd = FindWindowEx(dskHwnd, 0, "EXCEL7", vbNullString)
sbVHwnd = FindWindowEx(wbkHwnd, 0, "NUIScrollbar", "Vertical")

The following does not work:

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

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)

Private Const SB_HORZ = 0
Private Const SB_VERT = 1
Private Const SB_CTL = 2


Private Const SB_LINEUP = 0
Private Const SB_LINEDOWN = 1
Private Const SB_THUMBPOSITION = 4

    Dim lngRet As Long
    Dim si As SCROLLINFO
    With si
        .cbSize = Len(si)
        .fMask = SIF_ALL
        
        lngRet = GetScrollInfo(wbkHwnd, SB_VERT, si)
        .nPos = .nPos + 1
        lngRet = SetScrollInfo(wbkHwnd, SB_VERT, si, True)
        UpdateWindow wbkHwnd

    End With

The following messages have not effect either:

    SendMessage mainHwnd, WM_VSCROLL, SB_LINEDOWN, ByVal 0
    SendMessage wbkHwnd, WM_VSCROLL, SB_LINEDOWN, ByVal 0

the "Workbook" window appears to no longer be responding to WM_VSCROLL messages. Spy++ also shows a child window of EXCEL7 of class "NUIScrollbar", which makes me think that the EXCEL7 window no longer uses a standard vertical scroll bar, but a custom control.

Now if I use the following, I get to successfully scroll the scrollbox of the scrollbar, but I fail to update the window's scroll based on the new position of the scrollbar:

    lngRet = GetScrollInfo(sbVHwnd, SB_CTL, si)
    .nPos = .nPos + 1
    lngRet = SetScrollInfo(sbVHwnd, SB_CTL, si, True)
    UpdateWindow wbkHwnd

I also noticed this message successfully moves the scrollbox AND the window:

    'SendMessage wbkHwnd, WM_VSCROLL, SB_LINEDOWN, ByVal sbVHwnd

But I do not really like this last method since I cannot see this message in Spy++, so it is not how the system works natively...

I have also tried using the ScrollWindow and ScrollWindowEx functions to scroll the contents of the "Workbook" window, but I fail to see the cells moving.

So i need some help on :
- how to update the window scroll position based on the scroll bar position ?
- how to use ScrollWindow / ScrollWindowEx to scroll the contents of the window (cells...) ?

Thanks !