``` m_idTopLeftCell.row = -1; if (!m_bAllowDraw || !::IsWindow(GetSafeHwnd())) return; CRect rect; // This would have caused OnSize event - Brian //EnableScrollBars(SB_BOTH, FALSE); GetClientRect(rect); if (rect.left == rect.right || rect.top == rect.bottom) return; if (IsVisibleVScroll()) rect.right += GetSystemMetrics(SM_CXVSCROLL) + GetSystemMetrics(SM_CXBORDER); if (IsVisibleHScroll()) rect.bottom += GetSystemMetrics(SM_CYHSCROLL) + GetSystemMetrics(SM_CYBORDER); rect.left += GetFixedColumnWidth(); rect.top += GetFixedRowHeight(); if (rect.left >= rect.right || rect.top >= rect.bottom) { EnableScrollBarCtrl(SB_BOTH, FALSE); return; } CRect VisibleRect(GetFixedColumnWidth(), GetFixedRowHeight(), rect.right, rect.bottom); CRect VirtualRect(GetFixedColumnWidth(), GetFixedRowHeight(), GetVirtualWidth(), GetVirtualHeight()); // Removed to fix single row scrollbar problem (Pontus Goffe) // CCellRange visibleCells = GetUnobstructedNonFixedCellRange(); // if (!IsValid(visibleCells)) return; //TRACE(_T("Visible: %d x %d, Virtual %d x %d. H %d, V %d\n"), // VisibleRect.Width(), VisibleRect.Height(), // VirtualRect.Width(), VirtualRect.Height(), // IsVisibleHScroll(), IsVisibleVScroll()); // If vertical scroll bar, horizontal space is reduced if (VisibleRect.Height() < VirtualRect.Height()) VisibleRect.right -= ::GetSystemMetrics(SM_CXVSCROLL); // If horz scroll bar, vert space is reduced if (VisibleRect.Width() < VirtualRect.Width()) VisibleRect.bottom -= ::GetSystemMetrics(SM_CYHSCROLL); // Recheck vertical scroll bar //if (VisibleRect.Height() < VirtualRect.Height()) // VisibleRect.right -= ::GetSystemMetrics(SM_CXVSCROLL); if (VisibleRect.Height() < VirtualRect.Height()) { EnableScrollBars(SB_VERT, TRUE); m_nVScrollMax = VirtualRect.Height() - 1; } else { EnableScrollBars(SB_VERT, FALSE); m_nVScrollMax = 0; } if (VisibleRect.Width() < VirtualRect.Width()) { EnableScrollBars(SB_HORZ, TRUE); m_nHScrollMax = VirtualRect.Width() - 1; } else { EnableScrollBars(SB_HORZ, FALSE); m_nHScrollMax = 0; } ASSERT(m_nVScrollMax < INT_MAX && m_nHScrollMax < INT_MAX); // This should be fine /* Old code - CJM SCROLLINFO si; si.cbSize = sizeof(SCROLLINFO); si.fMask = SIF_PAGE; si.nPage = (m_nHScrollMax>0)? VisibleRect.Width() : 0; SetScrollInfo(SB_HORZ, &si, FALSE); si.nPage = (m_nVScrollMax>0)? VisibleRect.Height() : 0; SetScrollInfo(SB_VERT, &si, FALSE); SetScrollRange(SB_VERT, 0, m_nVScrollMax, TRUE); SetScrollRange(SB_HORZ, 0, m_nHScrollMax, TRUE); */ // New code - Paul Runstedler SCROLLINFO si; si.cbSize = sizeof(SCROLLINFO); si.fMask = SIF_PAGE | SIF_RANGE; si.nPage = (m_nHScrollMax>0)? VisibleRect.Width() : 0; si.nMin = 0; si.nMax = m_nHScrollMax; SetScrollInfo(SB_HORZ, &si, TRUE); si.fMask |= SIF_DISABLENOSCROLL; si.nPage = (m_nVScrollMax>0)? VisibleRect.Height() : 0; si.nMin = 0; si.nMax = m_nVScrollMax; SetScrollInfo(SB_VERT, &si, TRUE);```分析这段代码