Question

如何使窗口背景随滚动条滚动 vc++

Answer 1

在vc++中为窗口增加滚动条的方法：
Add a message handler for the WM_VSCROLL message to the OnVScroll method:
void CTestDlg::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);
}