请问在Onpaint中如何将滚动条关联起来？

Question

本人比较笨，在Onpaint中利用双缓存绘图，需要添加滚动条。现在我已经添加了滚动条的函数，对话框上的控件可以移动，但是利用双缓存画出来的图形不跟着移动。请问在Onpaint中如何将滚动条关联起来？最好有特定的函数。万分感谢！

Answer 1

在Bitblt或者StretchBlt的时候根据滚动条的位置贴相应位置的图就可以了。。～

Answer 2

类似于这样试下。。CPaintDC dc(this);CRect rect;
GetClientRect(&rect);CDC dcMem; 
dcMem.CreateCompatibleDC(&dc); CSize szScroll = GetTotalSize();CBitmap bmpMem;
bmpMem.CreateCompatibleBitmap(&dc, szScroll.cx, szScroll.cy);CBitmap* pBmpOld = dcMem.SelectObject(&bmpMem);DrawMemImage(dcMem, szScroll);dc.BitBlt(0, 0, rect.Width(), rect.Height(), &dcMem, GetScrollPos(SB_HORZ), GetScrollPos(SB_VERT), SRCCOPY);dcMem.SelectObject(pBmpOld);
bmpMem.DeleteObject();dcMem.DeleteDC();

Answer 3

非常感谢你的回复。我比较笨，再问一下，我将程序改动之后，编译时出现这样的问题：error C2065: 'GetTotalSize' : undeclared identifier
error C2065: 'DrawMemImage' : undeclared identifier
问一下是怎么回事啊？谢谢你！

Answer 4

GetTotalSize是CScrollView的成员函数。。DrawMemImage得自己实现，具体的绘制放在这个函数中。。

Answer 5

楼上，您好！我是在对话框中画图，需要水平滚动条。刚开始学习，我把画图的语句都写在OnPaint函数中了，我摘抄了一部分程序如下，麻烦您帮我看看。另外滚动条的程序在CTSRCureDlg::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)中，这样，对话框中的控件可以随着滚动条移动，但是图形不移动。应该在OnPaint函数中做哪些修改？谢谢！void CTSRCureDlg::OnPaint() 
{
CPaintDC dc(this); // device context for painting

// TODO: Add your message handler code here

// Do not call CDialog::OnPaint() for painting messages CDC *pDC;
pDC=GetDC();
CRect DrawRect;
CRect sideRect;
CBitmap MemBT;
CDC MemDC;
GetClientRect(&DrawRect);

int PicWidth,PicHeight;
int HRect,WRect; //绘图区Rect长宽
CPoint ZeroPos,NowPos,OldPos;
int WidEdge,HeiEdge; //边缘
int ppiHRect,ppiWRect; //绘图区长宽像素点 int dotFlag=0;
int alertFlag=0;
HRect=200;
WRect=1000;
ppiHRect=225;
ppiWRect=2060;
WidEdge=30;
HeiEdge=25;
float measureSpeed=0.5;
float measureDist=0.02;
CFont numFont;   CPen LinePen(PS_SOLID,1,RGB(85,85,85)); //银灰色
numFont.CreatePointFont(80,"黑体",NULL);


int yNum=0,xNum=0,sDot;

int tmpCurSpeed,tmpCurDist;
CString yNumStr,xNumStr,strTrainNum,strCurSpeed,strCurPos,strCSDscp;
CPoint tmpPoint;
PicWidth=DrawRect.Width(); //客户区宽度
PicHeight=DrawRect.Height(); //客户区长度
ZeroPos.x=WidEdge;
ZeroPos.y=ppiHRect;
//--------------------------双缓存绘图
MemDC.CreateCompatibleDC(pDC);
MemBT.CreateCompatibleBitmap(pDC,PicWidth,PicHeight);
MemDC.SelectObject(&MemBT);
DrawRect.SetRect(WidEdge,HeiEdge,ppiWRect,ppiHRect); //黑色画布区域
/*--------边框----------*/
sideRect.SetRect(WidEdge-5,HeiEdge-5,ppiWRect+5,ppiHRect+5);
/*----------------------*/
MemDC.FillSolidRect(0,0,PicWidth,PicHeight,RGB(255,255,255));
MemDC.FillSolidRect(sideRect,RGB(85,85,85)); //待修改，填充边框代码
MemDC.FillSolidRect(DrawRect,RGB(0,0,0));
MemDC.SetBkMode(TRANSPARENT); //文字背景透明

for (int i=0;i<8;i++) //横网格线
{
MemDC.SelectObject(&LinePen);
MemDC.MoveTo(WidEdge,ppiHRect-i*HRect/8);
MemDC.LineTo(ppiWRect,ppiHRect-i*HRect/8);
MemDC.SelectObject(&numFont);
yNumStr.Format("%d",yNum+i*50);
MemDC.SetTextColor(RGB(0,0,0));
if (i==7)
{
MemDC.SetTextColor(RGB(255,0,0));
}
MemDC.TextOut(5,ppiHRect-i*HRect/8,yNumStr);
}
for (i=0;i<21;i++) //纵网格线
{
MemDC.MoveTo(WidEdge+i*(WRect/5*measureSpeed),ppiHRect);
MemDC.LineTo(WidEdge+i*(WRect/5*measureSpeed),ppiHRect-8);
if (((i%2)==0))
{
MemDC.MoveTo(WidEdge+i*(WRect/5*measureSpeed),ppiHRect);
MemDC.LineTo(WidEdge+i*(WRect/5*measureSpeed),HeiEdge);
}
if (i>0)
{
yNumStr.Format("%d",yNum+i*5000);
MemDC.SetTextColor(RGB(0,0,0));
MemDC.TextOut(i*WRect/5*measureSpeed+25,ppiHRect+10,yNumStr);
}
} pDC->BitBlt(0,0,PicWidth,PicHeight,&MemDC,0,0,SRCCOPY);
MemBT.DeleteObject();
MemDC.DeleteDC();
}

Answer 6

在滚动条事件下 Invalidate(); 不过必须有成员变量或全局变量在 onpaint 中

Answer 7

依靠修改成员变量或全局变量 在Invalidate(); 

Answer 8

稍微修改了下。。virtual BOOL OnInitDialog();
afx_msg void OnPaint();
afx_msg void OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar);
afx_msg BOOL OnEraseBkgnd(CDC* pDC);int m_nScrollPos;
BEGIN_MESSAGE_MAP(CTSRCureDlg, CDialog)
ON_WM_PAINT()
ON_WM_HSCROLL()
ON_WM_ERASEBKGND()
ON_WM_SIZE()
END_MESSAGE_MAP()
BOOL CTSRCureDlg::OnInitDialog()
{
CDialog::OnInitDialog(); SCROLLINFO si;
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_ALL; 
si.nMin = 0;
si.nMax = 2060;
si.nPage = 100;
si.nPos = 0;
SetScrollInfo(SB_HORZ, &si, TRUE);  m_nScrollPos = 0; return TRUE;  // return TRUE unless you set the focus to a control
// 异常: OCX 属性页应返回 FALSE
}void CTSRCureDlg::OnPaint()
{
CPaintDC dc(this); // device context for painting
// TODO: 在此处添加消息处理程序代码
// 不为绘图消息调用 CDialog::OnPaint() //CDC *pDC;
//pDC=GetDC();
CDC* pDC = &dc; CRect DrawRect;
CRect sideRect;
CBitmap MemBT;
CDC MemDC;
GetClientRect(&DrawRect); int PicWidth,PicHeight;
int HRect,WRect; //绘图区Rect长宽
CPoint ZeroPos,NowPos,OldPos;
int WidEdge,HeiEdge; //边缘
int ppiHRect,ppiWRect; //绘图区长宽像素点 int dotFlag = 0; 
int alertFlag = 0;
HRect = 200;
WRect = 1000;
ppiHRect = 225;
ppiWRect = 2060; 
WidEdge = 30;
HeiEdge = 25;
float measureSpeed = 0.5f;
float measureDist = 0.02f;
CFont numFont; CPen LinePen(PS_SOLID, 1 ,RGB(85, 85, 85)); //银灰色
numFont.CreatePointFont(80, _T("黑体"), NULL);
int yNum=0, xNum=0/*,sDot*/; //int tmpCurSpeed,tmpCurDist;
CString yNumStr,xNumStr,strTrainNum,strCurSpeed,strCurPos,strCSDscp;
CPoint tmpPoint;
PicWidth=DrawRect.Width(); //客户区宽度
PicHeight=DrawRect.Height(); //客户区长度
ZeroPos.x=WidEdge;
ZeroPos.y=ppiHRect; //--------------------------双缓存绘图
MemDC.CreateCompatibleDC(pDC);
//MemBT.CreateCompatibleBitmap(pDC,PicWidth,PicHeight);
MemBT.CreateCompatibleBitmap(pDC,ppiWRect, PicHeight);
MemDC.SelectObject(&MemBT);
DrawRect.SetRect(WidEdge,HeiEdge,ppiWRect,ppiHRect); //黑色画布区域
/*--------边框----------*/
sideRect.SetRect(WidEdge-5,HeiEdge-5,ppiWRect+5,ppiHRect+5);
/*----------------------*/
//MemDC.FillSolidRect(0,0,PicWidth,PicHeight,RGB(255,255,255));
MemDC.FillSolidRect(0,0,ppiWRect,PicHeight,RGB(255,255,255));
MemDC.FillSolidRect(sideRect,RGB(85,85,85)); //待修改，填充边框代码
MemDC.FillSolidRect(DrawRect,RGB(0,0,0));
MemDC.SetBkMode(TRANSPARENT); //文字背景透明 for( int i = 0; i < 8; i++ ) //横网格线
{
MemDC.SelectObject(&LinePen);
MemDC.MoveTo(WidEdge, ppiHRect-i*HRect/8);
MemDC.LineTo(ppiWRect, ppiHRect-i*HRect/8);
MemDC.SelectObject(&numFont);
yNumStr.Format(_T("%d"), yNum+i*50);
MemDC.SetTextColor(RGB(0,0,0)); if (i == 7)
{
MemDC.SetTextColor(RGB(255,0,0));
} MemDC.TextOut(5, ppiHRect-i*HRect/8, yNumStr);
} for( int i = 0; i < 21; i++ ) //纵网格线
{
MemDC.MoveTo((int)(WidEdge+i*(WRect/5*measureSpeed)), ppiHRect);
MemDC.LineTo((int)(WidEdge+i*(WRect/5*measureSpeed)), ppiHRect-8); if(( (i%2) == 0 ))
{
MemDC.MoveTo((int)(WidEdge+i*(WRect/5*measureSpeed)),ppiHRect);
MemDC.LineTo((int)(WidEdge+i*(WRect/5*measureSpeed)),HeiEdge);
}
if (i > 0)
{
yNumStr.Format(_T("%d"), yNum+i*5000);
MemDC.SetTextColor(RGB(0,0,0));
MemDC.TextOut((int)(i*WRect/5*measureSpeed+25), ppiHRect+10, yNumStr);
}
} //pDC->BitBlt(0,0,PicWidth,PicHeight,&MemDC,0,0,SRCCOPY);
pDC->BitBlt(0,0,PicWidth,PicHeight,&MemDC,m_nScrollPos,0,SRCCOPY);
MemBT.DeleteObject();
MemDC.DeleteDC();
}void CTSRCureDlg::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
CRect rc;
GetClientRect(&rc); int nDelta(0);
int nMaxPos = 2060 - rc.Width() - 30; switch (nSBCode)
{
case SB_LINEDOWN:
if (m_nScrollPos >= nMaxPos)
return; nDelta = min(max(nMaxPos/20, 5), nMaxPos-m_nScrollPos);
break; case SB_LINEUP:
if (m_nScrollPos <= 0)
return;
nDelta = -min(max(nMaxPos/20, 5), m_nScrollPos);
break; case SB_PAGEDOWN:
if (m_nScrollPos >= nMaxPos)
return;
nDelta = min(max(nMaxPos/10, 5), nMaxPos-m_nScrollPos);
break; case SB_PAGEUP:
if (m_nScrollPos <= 0)
return;
nDelta = -min(max(nMaxPos/10, 5), m_nScrollPos);
break; case SB_THUMBTRACK:
case SB_THUMBPOSITION:
nDelta = (int)nPos - m_nScrollPos;
break; default:
return;
} m_nScrollPos += nDelta; SetScrollPos(SB_HORZ, m_nScrollPos,TRUE); Invalidate(); CDialog::OnHScroll(nSBCode, nPos, pScrollBar);
}BOOL CTSRCureDlg::OnEraseBkgnd(CDC* pDC)
{
//return CDialog::OnEraseBkgnd(pDC);
return TRUE;
}

Answer 9

对话框添加滚动条需要处理WM_HSCROLL/WM_VSCROLL

Answer 10

大侠有没有demo发给我看看呢
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