4.2.14 Adding WM_HSCROLL and WM_VSCROLL Cases

To make your application process scroll bar messages, add WM_HSCROLL and WM_VSCROLL cases to the window procedure, as follows:

case WM_HSCROLL:
case WM_VSCROLL:
    wsprintf(ScrollText, "%s: %s, %x, %x",
        (LPSTR) ((message == WM_HSCROLL) ? "WM_HSCROLL" :
            "WM_VSCROLL"),
        (LPSTR) ((wParam == SB_LINEUP) ? "SB_LINEUP" :
            (wParam == SB_LINEDOWN) ? "SB_LINEDOWN" :
            (wParam == SB_PAGEUP) ? "SB_PAGEUP" :
            (wParam == SB_PAGEDOWN) ? "SB_PAGEDOWN" :
            (wParam == SB_THUMBPOSITION) ? "SB_THUMBPOSITION" :
            (wParam == SB_THUMBTRACK) ? "SB_THUMBTRACK" :
            (wParam == SB_ENDSCROLL) ? "SB_ENDSCROLL" : "unknown"),
        ScrollTypeText,
        LOWORD(lParam),
        HIWORD(lParam));
    InvalidateRect(hWnd, &rectScroll, TRUE);
    break;