鼠标滚轮与滚动条
1.创建一个带滚动条的窗口
//CMainWnd::CMainWnd(){Create(NULL, _T("Accel App"),WS_OVERLAPPEDWINDOW|WS_HSCROLL|WS_VSCROLL);}
2.OnSize 函数里面初始化滚动条
void CMainWnd::OnSize(UINT nType, int cx, int cy){CFrameWnd::OnSize(nType, cx, cy);CClientDC dc(this);TEXTMETRIC tm;dc.GetTextMetrics(&tm);m_ncxChar = tm.tmHeight + tm.tmExternalLeading;int m_nVScrollMax = 0; //舒适化滚动条最大值为0m_nVPageSize = m_nVScrollPos=0; //初始化类成员//设置垂直滚动条参数m_nVPageSize = cy;m_nVScrollMax = 100*m_ncxChar;//线条总长度1600,滚动位置最大1600-1//滚动范围必须在线条超出窗口的范围内m_nVScrollPos = min(m_nVScrollPos, m_nVScrollMax - 1 - m_nVPageSize);SCROLLINFO si;si.fMask = SIF_ALL;si.nMin = 0;si.nMax = m_nVScrollMax;si.nPos = m_nVScrollPos;si.nPage = m_nVPageSize;SetScrollInfo(SB_VERT, &si, TRUE);}
3.响应滚动 OnVScroll
void CMainWnd::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar){int nDelta;switch (nSBCode){case SB_LINEDOWN:nDelta = +10;break;case SB_LINEUP:nDelta = -10;break;case SB_PAGEDOWN:nDelta = +m_nVPageSize;break;case SB_PAGEUP:nDelta = -m_nVPageSize;break;case SB_THUMBTRACK:nDelta = (int)nPos - m_nVScrollPos;break;default:return;}//设置改变后的滚动他位置int nScrollPos = m_nVScrollPos + nDelta;//最大位移量int nMaxPos = 100 * m_ncxChar - m_nVPageSize;if (nScrollPos<0)//当滚动条位置为0,且点击up时,nScrollPos<0{nDelta = -m_nVScrollPos;}else if (nScrollPos >nMaxPos)//当m_nVScrollPos在终端时,点down,nScrollPos >nMaxPos{//nDelta =100 * m_ncxChar - m_nVPageSize;nDelta = nMaxPos - m_nVScrollPos;}if (nDelta!=0){m_nVScrollPos += nDelta;SetScrollPos(SB_VERT, m_nVScrollPos, TRUE);ScrollWindow(0, -nDelta);}}
4.加入鼠标滚轮
DECLARE_MESSAGE_MAP()//鼠标滚动消息afx_msg BOOL OnMouseWheel(UINT, short, CPoint);afx_msg void OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)///cpp里面加入 ON_WM_MOUSEWHEEL()BEGIN_MESSAGE_MAP(CMainWnd,CFrameWnd)ON_WM_MOUSEWHEEL()ON_WM_VSCROLL()ON_WM_SIZE()ON_WM_PAINT()END_MESSAGE_MAP()
5.处理鼠标滚动消息
BOOL CMainWnd::OnMouseWheel(UINT nFlags, short zDelta, CPoint point){BOOL bUp = TRUE;//zDelta <0 向下滚动int nDelta = zDelta;if (zDelta<0){bUp = FALSE;nDelta = -zDelta;}UINT nWheelScrollLines;::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &nWheelScrollLines, 0);if (nWheelScrollLines ==WHEEL_PAGESCROLL){SendMessage(WM_VSCROLL, MAKEWPARAM(bUp ? SB_PAGEUP : SB_PAGEDOWN, 0), 0);}else{int nLines = (nDelta * nWheelScrollLines)/WHEEL_DELTA;while (nLines--){SendMessage(WM_VSCROLL, MAKEWPARAM(bUp ? SB_LINEUP : SB_LINEDOWN, 0), 0);}}return TRUE;}/*如果将来使用的鼠标滚轮的间隔尺寸不到120单位,那么用zDelta除以WHEELDELTA就确保了应用程序不会滚动太快。WHEEL_ PAGESCROLL是一个特殊值,它告诉应用程序就确保了应用程序不会滚动太快。WHEEL_ PAGESCROLL是一个特殊值,它告诉应用程序WHEELL PAGESCROLL的定义在Winuser.h 中。*/
6.最后设置视点随着滚动条滚动
void CMainWnd::OnPaint(){CPaintDC dc(this);//设置视点随着滚动条滚动dc.SetWindowOrg(0, m_nVScrollPos);for (int i=0;i<100;i++){LPWSTR a=NULL;//wsprintf(a,L"%d", i);//CString str("Hello");//str.Append(i);TCHAR str[30];wsprintf(str, L"The %d Line", i);dc.TextOutW(100, i* m_ncxChar, str);}dc.SetBkMode(TRANSPARENT);}
