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积累的VC编程小技巧之滚动条
1.设置滚动条的滚动大小
创建一个基于CScrollview的SDI Project（在第6步中选CScrollview）
若你已创建了，这步可以省略。
然后：
改为如
void CTestView::OnInitialUpdate()
{
CScrollView::OnInitialUpdate();
CSize sizeTotal;
// TODO: calculate the total size of this view
sizeTotal.cx = 1024; //改这两个
sizeTotal.cy = 768; //
SetScrollSizes(MM_TEXT, sizeTotal);
}
2.滚动条的控制
BOOL CDiagramShowView::PreTranslateMessage(MSG* pMsg)
{
CFileTreeDoc* pDoc = (CFileTreeDoc*)GetDocument();
CPoint point = GetScrollPosition();
if(pMsg->message == WM_KEYDOWN)
{
switch(pMsg->wParam)
{
case VK_LEFT:
if( point.x > 10)
{
EndPoint.x = EndPoint.x - 10;
EndPoint.y = EndPoint.y;
}
else
{
EndPoint.x = 0;
EndPoint.y = EndPoint.y;
}
ScrollToPosition(EndPoint);
InvalidateRect(NULL,TRUE);
break;
case VK_RIGHT:
if( point.x < pDoc->intDiagramColumnCount * pDoc->intColumnWidth - 10 )
{
EndPoint.x = EndPoint.x + 10;
EndPoint.y = EndPoint.y;
}
else
{
EndPoint.y = pDoc->intDiagramColumnCount * pDoc->intColumnWidth;
EndPoint.x = EndPoint.x;
}
ScrollToPosition(EndPoint);
InvalidateRect(NULL,TRUE);
break;
case VK_UP:
if( point.y > 10)
{
EndPoint.y = EndPoint.y - 10;
EndPoint.x = EndPoint.x;
}
else
{
EndPoint.y = 0;
EndPoint.x = EndPoint.x;
}
ScrollToPosition(EndPoint);
InvalidateRect(NULL,TRUE);
break;
case VK_DOWN:
if( point.y < pDoc->intDiagramRowCount * pDoc->intRowHeight - 10 )
{
EndPoint.y = EndPoint.y + 10;
EndPoint.x = EndPoint.x;
}
else
{
EndPoint.y = pDoc->intDiagramRowCount * pDoc->intRowHeight;
EndPoint.x = EndPoint.x;
}
ScrollToPosition(EndPoint);
InvalidateRect(NULL,TRUE);
break;
default:
break;
}
}
return FALSE;
}
// 通过正负号判断是向上还是向下滚动
if(zDelta==120)
向上滚动
if(zDelta==-120)
向下滚动
BOOL CDiagramShowView::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt)
{
CFileTreeDoc* pDoc = (CFileTreeDoc*)GetDocument();
CPoint point = GetScrollPosition();
if(zDelta==120)
{
if( point.y >= 20 )
{
EndPoint.x = point.x;
EndPoint.y = point.y;
EndPoint.x = EndPoint.x;
EndPoint.y = EndPoint.y - 20;
}
else
{
EndPoint.x = EndPoint.x;
EndPoint.y = 0;
}
}
if(zDelta==-120)
{
if( point.y <= pDoc->intDiagramRowCount * pDoc->intRowHeight - 20 )
{
EndPoint.x = point.x;
EndPoint.y = point.y;
EndPoint.x = EndPoint.x;
EndPoint.y = EndPoint.y + 20;
}
else
{
EndPoint.x = EndPoint.x;
EndPoint.y = EndPoint.y;
}
}
ScrollToPosition(EndPoint);
InvalidateRect(NULL,TRUE);
return CScrollView::OnMouseWheel(nFlags, zDelta, pt);
}
3.给从CWnd派生的窗口添加滚动条
ModifyStyle(0,WS_VSCROLL);
4.如何用键盘滚动分割的视口
我的问题是当我用鼠标滚动分割窗口时,视口滚动都很正常,但用键盘时,却什么也没有发生.
在你的视图继承类中加入如下两个函数,假定该类为CScrollerView:
void CScrollerView::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
BOOL processed;
for (unsigned int i=0;i< nRepCnt&&processed;i++)
processed=KeyScroll(nChar);
if (!processed)
CScrollView::OnKeyDown(nChar, nRepCnt, nFlags);
}
BOOL CScrollerView::KeyScroll(UINT nChar)
{
switch (nChar)
{
case VK_UP:
OnVScroll(SB_LINEUP,0,NULL);
break;
case VK_DOWN:
OnVScroll(SB_LINEDOWN,0,NULL);
break;
case VK_LEFT:
OnHScroll(SB_LINELEFT,0,NULL);
break;
case VK_RIGHT:
OnHScroll(SB_LINERIGHT,0,NULL);
break;
case VK_HOME:
OnHScroll(SB_LEFT,0,NULL);
break;
case VK_END:
OnHScroll(SB_RIGHT,0,NULL);
break;
case VK_PRIOR:
OnVScroll(SB_PAGEUP,0,NULL);
break;
case VK_NEXT:
OnVScroll(SB_PAGEDOWN,0,NULL);
break;
default:
return FALSE; // not for us
// and let the default class
// process it.
}
return TRUE;
}