MarkupListBox

Hello,

found a solution.
Handle WM_MOUSEWHEEL my self.

void CMarkupListBox::OnHandleMouseWheel(WPARAM wParam, LPARAM lParam)
{
    short zDelta = GET_WHEEL_DELTA_WPARAM(wParam);

    // Don't do anything if the vertical scrollbar is not enabled.
    int scrollMin = 0, scrollMax = 0;
    GetScrollRange(SB_VERT, &scrollMin, &scrollMax);
    if ( scrollMin == scrollMax )
        return;

    // Compute the number of scrolling increments requested.
    int numScrollIncrements = abs(zDelta) / WHEEL_DELTA;

    // Each scrolling increment corresponds to a certain number of
    // scroll lines (one scroll line is like a SB_LINEUP or SB_LINEDOWN).
    // We need to query the system parameters for this value.
    int numScrollLinesPerIncrement = 0;
    ::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &numScrollLinesPerIncrement, 0);

    // Check if a page scroll was requested.
    if ( numScrollLinesPerIncrement == WHEEL_PAGESCROLL )
    {
        SendMessage(WM_VSCROLL, zDelta > 0 ? SB_PAGEUP : SB_PAGEDOWN, 0);
        return;
    }

    // Compute total number of lines to scroll.
    int numScrollLines = numScrollIncrements * numScrollLinesPerIncrement;

    // Adjust numScrollLines to slow down the scrolling a bit more.
    numScrollLines = max(numScrollLines/3, 1);

    // Do the scrolling.
    for(int i = 0; i < numScrollLines; ++i)
        SendMessage(WM_VSCROLL, zDelta > 0 ? SB_LINEUP : SB_LINEDOWN, 0);
}

  Jimmy