支持窗口滚动条控制的类（SDK版）

这里提供一个SDK版的，支持窗口滚动条控制的类，MFC版本和使用方法都请参考这里。
// H 文件#pragma onceclass CScrollWnd {public:CScrollWnd();virtual ~CScrollWnd();public:void Attach(HWND hWnd);void Detach();void SetSize(int nWidth, int nHeight);const SIZE& GetSize() const;const SIZE& GetScrollPos() const;const SIZE& GetPageSize() const;void ScrollToOrigin(BOOL bLeft, BOOL bTop);void OnHScroll(WPARAM wParam, LPARAM lParam);void OnVScroll(WPARAM wParam, LPARAM lParam);BOOL OnMouseWheel(WPARAM wParam, LPARAM lParam);void OnSize(WPARAM wParam, LPARAM lParam);private:void SetScrollClientRect(HWND hWnd, RECT& rect);int Get32BitScrollPos(int bar, BOOL bTrackPos, HWND hWndScrollBar);void UpdateScrollInfo();void UpdateScrollBar(int bar, int windowSize, int displaySize, LONG& pageSize, LONG& scrollPos, LONG& deltaPos);HWND m_hWndAttach;SIZE m_pageSize;SIZE m_size;SIZE m_scrollPos;};// CPP 文件#include "StdAfx.h"#include "ScrollWnd.h"CScrollWnd::CScrollWnd() : m_hWndAttach(NULL){m_pageSize.cx = 0;m_pageSize.cy = 0;m_size.cx = 0;m_size.cy = 0;m_scrollPos.cx = 0;m_scrollPos.cy = 0;}CScrollWnd::~CScrollWnd(){Detach();}void CScrollWnd::Attach(HWND hWnd){m_hWndAttach = hWnd;}void CScrollWnd::Detach(){m_hWndAttach = NULL;}void CScrollWnd::SetSize(int nWidth, int nHeight){m_size.cx = nWidth;m_size.cy = nHeight;if(NULL != m_hWndAttach && ::IsWindow(m_hWndAttach)){UpdateScrollInfo();}}const SIZE& CScrollWnd::GetSize() const{return m_size;}const SIZE& CScrollWnd::GetScrollPos() const{return m_scrollPos;}const SIZE& CScrollWnd::GetPageSize() const{return m_pageSize;}void CScrollWnd::ScrollToOrigin(BOOL bLeft, BOOL bTop){if(NULL == m_hWndAttach){return ;}if(bLeft){if(m_size.cx > 0 && m_pageSize.cx > 0 && m_scrollPos.cx > 0){int deltaPos = -m_scrollPos.cx;m_scrollPos.cx += deltaPos;::SetScrollPos(m_hWndAttach, SB_HORZ, m_scrollPos.cx, TRUE);::ScrollWindowEx(m_hWndAttach, -deltaPos, 0, NULL, NULL, NULL, NULL, SW_ERASE | SW_INVALIDATE | SW_SCROLLCHILDREN);::UpdateWindow(m_hWndAttach);}}if(bTop){if(m_size.cy > 0 && m_pageSize.cy > 0 && m_scrollPos.cy > 0){int deltaPos = -m_scrollPos.cy;m_scrollPos.cy += deltaPos;::SetScrollPos(m_hWndAttach, SB_VERT, m_scrollPos.cy, TRUE);::ScrollWindowEx(m_hWndAttach, 0, -deltaPos, NULL, NULL, NULL, NULL, SW_ERASE | SW_INVALIDATE | SW_SCROLLCHILDREN);}}}void CScrollWnd::OnHScroll(WPARAM wParam, LPARAM lParam){if(NULL == m_hWndAttach){return ;}const int lineOffset = 60;int deltaPos = 0;UINT nSBCode = LOWORD(wParam);UINT nPos = HIWORD(wParam);switch( nSBCode ){case SB_LINELEFT:deltaPos = -lineOffset;break;case SB_LINERIGHT:deltaPos = lineOffset;break;case SB_PAGELEFT:deltaPos = -m_pageSize.cx;break;case SB_PAGERIGHT:deltaPos = m_pageSize.cx;break;case SB_THUMBTRACK:deltaPos = Get32BitScrollPos(SB_HORZ, TRUE, (HWND)lParam) - m_scrollPos.cx;break;case SB_THUMBPOSITION:deltaPos = Get32BitScrollPos(SB_HORZ, FALSE, (HWND)lParam) - m_scrollPos.cx;break;default:return;}int newScrollPos = m_scrollPos.cx + deltaPos;if(newScrollPos < 0){deltaPos = -m_scrollPos.cx;}int maxScrollPos = m_size.cx - m_pageSize.cx;if(newScrollPos > maxScrollPos){deltaPos = maxScrollPos - m_scrollPos.cx;}if(deltaPos != 0){m_scrollPos.cx += deltaPos;::SetScrollPos(m_hWndAttach, SB_HORZ, m_scrollPos.cx, TRUE);::ScrollWindowEx(m_hWndAttach, -deltaPos, 0, NULL, NULL, NULL, NULL, SW_ERASE | SW_INVALIDATE | SW_SCROLLCHILDREN);::UpdateWindow(m_hWndAttach);}}void CScrollWnd::OnVScroll(WPARAM wParam, LPARAM lParam){if(NULL == m_hWndAttach){return ;}const int lineOffset = 60;UINT nSBCode = LOWORD(wParam);UINT nPos = HIWORD(wParam); int deltaPos = 0;SCROLLINFO si = {sizeof(si), SIF_ALL};GetScrollInfo(m_hWndAttach, SB_VERT, &si);switch( nSBCode ){case SB_LINEUP:deltaPos = -lineOffset;break;case SB_LINEDOWN:deltaPos = lineOffset;break;case SB_PAGEUP:deltaPos = -m_pageSize.cy;break;case SB_PAGEDOWN:deltaPos = m_pageSize.cy;break;case SB_THUMBTRACK:deltaPos = Get32BitScrollPos(SB_VERT, TRUE, (HWND)lParam) - m_scrollPos.cy;break;case SB_THUMBPOSITION:deltaPos = Get32BitScrollPos(SB_VERT, FALSE, (HWND)lParam) - m_scrollPos.cy;break;default:return;}int newScrollPos = m_scrollPos.cy + deltaPos;if(newScrollPos < 0){deltaPos = -m_scrollPos.cy;}int maxScrollPos = m_size.cy - m_pageSize.cy;if(newScrollPos > maxScrollPos){deltaPos = maxScrollPos - m_scrollPos.cy;}if(deltaPos != 0){m_scrollPos.cy += deltaPos;::SetScrollPos(m_hWndAttach, SB_VERT, m_scrollPos.cy, TRUE);::ScrollWindowEx(m_hWndAttach, 0, -deltaPos, NULL, NULL, NULL, NULL, SW_ERASE | SW_INVALIDATE | SW_SCROLLCHILDREN);::UpdateWindow(m_hWndAttach);}}BOOL CScrollWnd::OnMouseWheel(WPARAM wParam, LPARAM lParam){if(NULL == m_hWndAttach){return FALSE;}int scrollMin = 0;int scrollMax = 0;SCROLLINFO si = {sizeof(si), SIF_ALL};GetScrollInfo(m_hWndAttach, SB_VERT, &si);scrollMin = si.nMin;scrollMax = si.nMax;if(scrollMin == scrollMax){return FALSE;}UINT nFlags = LOWORD(wParam);short zDelta = HIWORD(wParam);POINT pt = {LOWORD(lParam), HIWORD(lParam)};int numScrollIncrements = abs(zDelta) / WHEEL_DELTA;int numScrollLinesPerIncrement = 0;::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &numScrollLinesPerIncrement, 0);if(numScrollLinesPerIncrement == WHEEL_PAGESCROLL){OnVScroll(MAKEWPARAM(zDelta > 0 ? SB_PAGEUP : SB_PAGEDOWN, 0), NULL);return TRUE;}int numScrollLines = numScrollIncrements * numScrollLinesPerIncrement;numScrollLines = max(numScrollLines/3, 1);for(int i = 0; i < numScrollLines; ++i){OnVScroll(MAKEWPARAM(zDelta > 0 ? SB_LINEUP : SB_LINEDOWN, 0), NULL);}return TRUE;}void CScrollWnd::OnSize(WPARAM wParam, LPARAM lParam){UpdateScrollInfo();}void CScrollWnd::SetScrollClientRect(HWND hWnd, RECT& rect){ASSERT(NULL != hWnd);RECT rc;::GetWindowRect(hWnd, &rc);POINT ptLeftTop = {rc.left, rc.top};POINT ptRightBottom = {rc.right, rc.bottom};::ScreenToClient(hWnd, &ptLeftTop);::ScreenToClient(hWnd, &ptRightBottom);rc.left = ptLeftTop.x;rc.top = ptLeftTop.y;rc.right = ptRightBottom.x;rc.bottom = ptRightBottom.y;::GetClientRect(hWnd, &rect);int cx = ::GetSystemMetrics(SM_CXVSCROLL);int cy = ::GetSystemMetrics(SM_CYHSCROLL);if(rc.right >= (rect.right + cx)){rect.right += cx;}if(rc.bottom >= (rect.bottom + cy)){rect.bottom += cy;}}int CScrollWnd::Get32BitScrollPos(int bar, BOOL bTrackPos, HWND hWndScrollBar){if(NULL == m_hWndAttach){return 0;}HWND hWndScroll;if (NULL == hWndScrollBar){hWndScroll = m_hWndAttach;}else{hWndScroll = hWndScrollBar;}SCROLLINFO si = {0};si.cbSize = sizeof(SCROLLINFO);si.fMask = bTrackPos ? SIF_TRACKPOS : SIF_POS;::GetScrollInfo(hWndScroll, bar, &si);return bTrackPos ? si.nTrackPos : si.nPos;}void CScrollWnd::UpdateScrollInfo(){if(NULL == m_hWndAttach){return ;}RECT rect;SetScrollClientRect(m_hWndAttach, rect);SIZE windowSize = {rect.right - rect.left, rect.bottom - rect.top};SIZE deltaPos = {0, 0};UpdateScrollBar(SB_HORZ, windowSize.cx, m_size.cx, m_pageSize.cx, m_scrollPos.cx, deltaPos.cx);UpdateScrollBar(SB_VERT, windowSize.cy, m_size.cy, m_pageSize.cy, m_scrollPos.cy, deltaPos.cy);if(deltaPos.cx != 0 || deltaPos.cy != 0){::ScrollWindowEx(m_hWndAttach, deltaPos.cx, deltaPos.cy, NULL, NULL, NULL, NULL, SW_ERASE | SW_INVALIDATE | SW_SCROLLCHILDREN);::UpdateWindow(m_hWndAttach);}}void CScrollWnd::UpdateScrollBar(int bar, int windowSize, int displaySize, LONG& pageSize, LONG& scrollPos, LONG& deltaPos){int scrollMax = 0;deltaPos = 0;SCROLLINFO si = {sizeof(si), SIF_ALL};::GetScrollInfo(m_hWndAttach, bar, &si);int nPos = si.nPos;if(windowSize < displaySize ){scrollMax = displaySize - 1;if(pageSize > 0 && scrollPos > 0){scrollPos = (LONG)(1.0 * scrollPos * windowSize / pageSize);}pageSize = windowSize;scrollPos = min(scrollPos, displaySize - pageSize - 1);deltaPos = nPos - scrollPos;}else{pageSize = 0;scrollPos = 0;deltaPos = nPos;}memset(&si, 0, sizeof(SCROLLINFO));si.cbSize = sizeof(SCROLLINFO);si.fMask = SIF_ALL;si.nMin = 0;si.nMax = scrollMax;si.nPage = pageSize;si.nPos = scrollPos;::SetScrollInfo(m_hWndAttach, bar, &si, TRUE);}