Scroll Bar 控件

• Structure

• typedef struct tagSCROLLINFO {
    UINT cbSize; //Sizeof(SCROLLINFO)
    UINT fMask; 
    int nMin; //minimum scrolling position
    int nMax; //maximum scrolling position
    UINT nPage; 
    int nPos; //position of the scroll box
    int nTrackPos; 
  } SCROLLINFO; 
  typedef SCROLLINFO FAR* LPSCROLLINFO; 

• fMask:需要设置或获取的参数。SIF_ALL、SIF_DISABLENOSCROLL、SIF_PAGE、SIF_POS、SIF_RANGE、SIF_TRACKPOS
• nPage:页尺寸。用来设置scroll box的适当尺寸。
• nTrackPos:拖动scroll box时的当前位置，对应SB_THUMBTRACK消息
• Functions

• BOOL GetScrollInfo(HWND hwnd, int fnBar, LPSCROLLINFO lpsi );
  int SetScrollInfo(HWND hwnd, int fnBar, LPSCROLLINFO lpsi, BOOL fRedraw ); 
  int SetScrollPos(HWND hWnd, int nBar, int nPos, BOOL bRedraw ); 
  BOOL SetScrollRange(HWND hWnd, int nBar, int nMinPos, int nMaxPos, BOOL bRedraw ); 
  BOOL GetScrollInfo(HWND hwnd, int fnBar, LPSCROLLINFO lpsi ); 
  BOOL ScrollDC(
    HDC hDC, 
    int dx, 
    int dy, 
    const RECT* lprcScroll, 
    const RECT* lprcClip, 
    HRGN hrgnUpdate, 
    LPRECT lprcUpdate 
  ); 
  int ScrollWindowEx( 
    HWND hWnd, 
    int dx, 
    int dy, 
    const RECT* prcScroll, 
    const RECT* prcClip, 
    HRGN hrgnUpdate, 
    LPRECT prcUpdate, 
    UINT flags 
  ); 

• Messages
• WM_HSCROLL:nScrollCode、nPos、hwndScrollBar
• WM_VSCROLL