关于 OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)

one_add_one 2002-10-13 04:29:12

UINT nPos，好象只是short int型。。

如果我的ScrollRange特别大，这个nPos经常就会变成负数：（

我不想改变ScrollRange请问怎样解决。

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YoungBoz 2002-10-13

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用GetScrollInfo支持长整数，弃用GetScrollPos，这是MSDN中对32程序的建议，另外讨厌的DC也仅支持16位。这样你要支32位的滚动视有你受的。老兄，准备吃点苦，很多MFC中的原代码都得作些改动才行啊。

approach 2002-10-13

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在NT内核的操作系统中应该不会这样!而95/98并不是真正的32 位操作系统,里面仍然包含16位代码.比如Scrollbars还是只接受16位的值来调整范围

approach 2002-10-13

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nPos参数只有16位长.克服这个限制可以使用SCROOLINFO结构运行::GetScrollInfo.SCROLLINFO 结构中的nTrackPos是一个真正的32位

everandforever 2002-10-13

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是吗？没听说过，不会吧？定义成UINT，实际却是SHORT INT？我觉得不大可能

approach 2002-10-13

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哦,那可是无符号的
unsigned int

hfqian 2002-10-13

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奇怪的要求！可以成比例的增大缩小嘛

Selecting the "Horizontal Scroll" and "Verticla Scroll" styles among the properties of your dialog box in the resource editor, you can add scroll bars to the dialog box. Remember also to select the 'resizing' border style. However for adding functionality to the scroll bars, you need to override the WM_VSCROLL and WM_HSCROLL message handlers. Also,override the WM_SIZE handler to set the scroll bar range if the size is reduced than the original. So you get the original size of the dialog in your OninitDialog(). The code would look something like this. Modify to your needs. 1. To OnInitDialog(),add the following line. GetWindowRect(m_rect); m_nScrollPos = 0; to get the original window size. Make m_rect a member variable of your dialog. Add another variable m_nScrollPos and initialize its value to zero. It stores the current vertical scroll position. 2. Here is the WM_SIZE handler for setting the scroll bar range.Set range 0 if size is increased more than original. void CCharlesDlg::OnSize(UINT nType, int cx, int cy) { CDialog::OnSize(nType, cx, cy); // TODO: Add your message handler code here m_nCurHeight = cy; int nScrollMax; if (cy < m_rect.Height()) { nScrollMax = m_rect.Height() - cy; } else nScrollMax = 0; SCROLLINFO si; si.cbSize = sizeof(SCROLLINFO); si.fMask = SIF_ALL;// SIF_ALL = SIF_PAGE | SIF_RANGE | SIF_POS; si.nMin = 0; si.nMax = nScrollMax; si.nPage = si.nMax/10; si.nPos = 0; SetScrollInfo(SB_VERT, &si, TRUE); } You need m_nCurHeight to store the current height of the dialog and use it to handle the scrolling in OnVScroll. m_ncurHeight is also a member variable of the dialog. 3. Here is the handler for WM_VSCROLL. void CCharlesDlg::OnVScroll(UINT nSBCode,UINT nPos,CScrollBar* pScrollBar) { //TODO:Add your message handler code here and/or call default int nDelta; int nMaxPos = m_rect.Height() - m_nCurHeight; switch(nSBCode) { case SB_LINEDOWN: if (m_nScrollPos >= nMaxPos) return; nDelta = min(nMaxPos/100,nMaxPos-m_nScrollPos); break; case SB_LINEUP: if (m_nScrollPos <= 0) return; nDelta = -min(nMaxPos/100,m_nScrollPos); break; case SB_PAGEDOWN: if (m_nScrollPos >= nMaxPos) return; nDelta = min(nMaxPos/10,nMaxPos-m_nScrollPos); break; case SB_THUMBPOSITION: nDelta = (int)nPos - m_nScrollPos; break; case SB_PAGEUP: if (m_nScrollPos <= 0) return; nDelta = -min(nMaxPos/10,m_nScrollPos); break; default: return; } m_nScrollPos += nDelta; SetScrollPos(SB_VERT,m_nScrollPos,TRUE); ScrollWindow(0,-nDelta); CDialog::OnVScroll(nSBCode, nPos, pScrollBar); } The above code handles the vertical scrolling. For horizontal scrolling add the WM_HSCROLL similarly and add the necessary code to OnSize and OnInitDialog. Information provided in this document and any software that may accompany this document is provided "as is" without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose. The user assumes the entire risk as to the accuracy and the use of this information.

OnHScroll( UINT nSBCode, UINT nPos, CScrollBar* pScrollBar )和OnVScroll( UINT nSBCode, UINT nPos, CScrollBar* pScrollBar )这两个函数，网上很多人写的博客或是例子，都没有很好地说明这三个参数，下面我就实际开发中的经验做一下解释：UINT nSBCode：指定指示用户滚动请求的滚动条...

void CDialog1::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar) { // TODO: 在此添加消息处理程序代码和/或调用默认值 SCROLLINFO scrollinfo; GetScrollInfo(SB_HORZ,&scrollinfo,SIF_ALL); switch (nSBCode) { case SB_LEFT: //滑块滚动到最左 Sc...

一，使用对话框窗口自带的滚动条，在属性页面中设置即可，如下二，OnInitDialog()函数中，添加如下滚动条初始化语句 1 　　　　SCROLLINFO vinfo; 2 vinfo.cbSize=sizeof(vinfo); 3 vinfo.fMask=SIF_ALL; 4 vinfo.nPage=50;//滚动块自身的长短，通...

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