You might want a scroll bar object respond to its own notification messages.

TDialog has built-in support for dispatching scroll bar notification messages back to the scroll bar.

TWindow::EvHScroll or TWindow::EvVScroll executes the appropriate TScrollBar member function based on the notification code. For example:

class TSpecializedScrollBar : public TScrollBar {
public:
  virtual void SBTop();
  };
 
void TSpecializedScrollBar::SBTop() {
  TScrollBar::SBTop();
  ::sndPlaySound("AT-TOP.WAV", SND_ASYNC); // play sound
  }

Be sure to call the base member functions first. They correctly update the scroll bar to its new position.

The following table associates notification messages with the corresponding TScrollBar member function:

Notification message	TScrollBar member function
SB_LINEUP	TScrollBar::SBLineUp
SB_LINEDOWN	TScrollBar::SBLineDown
SB_PAGEUP	TScrollBar::SBPageUp
SB_PAGEDOWN	TScrollBar::SBPageDown
SB_THUMBPOSITION	TScrollBar::SBThumbPosition
SB_THUMBTRACK	TScrollBar::SBThumbTrack
SB_TOP	TScrollBar::SBTop
SB_BOTTOM	TScrollBar::SBBottom

See Also