Call this member function to obtain a pointer to the specified sibling scroll bar or splitter window.
Specifies the type of scroll bar. The parameter can take one of the following values:
SB_HORZ Retrieves the position of the horizontal scroll bar.
SB_VERT Retrieves the position of the vertical scroll bar.
A sibling scroll-bar control, or NULL if none.
This member function does not operate on scroll bars created when the WS_HSCROLL or WS_VSCROLL bits are set during the creation of a window. The CWnd implementation of this function simply returns NULL. Derived classes, such as CView, implement the described functionality.