Scroll Bar 控件

• Structure

•  1 typedef struct tagSCROLLINFO {
   2   UINT cbSize; //Sizeof(SCROLLINFO)
   3   UINT fMask; 
   4   int nMin; //minimum scrolling position
   5   int nMax; //maximum scrolling position
   6   UINT nPage; 
   7   int nPos; //position of the scroll box
   8   int nTrackPos; 
   9 } SCROLLINFO; 
  10 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