源代码下载
多边形也就是由一些连续的直线组成的，所以绘图的代码还是前面的画直线的那两种算法，只不过在鼠标移动的过程中要特别注意记录终点的位置而已，代码中还是存在着bug,画多边形的时候出现了黄色的阴影线，真是奇怪的问题。为了判别是否是多边形的第一条边，加入了一个新变量：bool m_bIsFirstDone;//是否第一条边
void CMyDrawView::OnMouseMove(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
CString str;
CDC *pDC=GetDC();
//状态栏显示坐标值
str.Format("X:%d,Y:%d",point.x,point.y);
if(!m_pwndStatusBar)
m_pwndStatusBar=((CMainFrame*)AfxGetMainWnd())->GetStatusBar();
m_pwndStatusBar->SetPaneText(2,str,1);
if(m_dsDrawSort==dsNULL)
return;
switch(m_dsDrawSort)
{
case dsLine:
SetCursor(m_hDLCursor);
break;
case dsCircle:
SetCursor(m_hDCCursor);
break;
}
//鼠标放开了
if(!m_bIsMoseDown)
return;
pDC->SetROP2(R2_NOTXORPEN);
switch(m_dsDrawSort)
{
case dsLine:
{//直线
Line *l1 = new Line(m_startPoint,m_endPoint);
l1->SetDrawLineSort(m_dlsDrawLineSort);
l1->SetPenColor(m_lPenColor);
Line *l2 = new Line(m_startPoint,point);
l2->SetDrawLineSort(m_dlsDrawLineSort);
l2->SetPenColor(m_lPenColor);
l1->Draw(pDC);
l2->Draw(pDC);
break;
}
case dsCircle:
{//圆
Line *l1 = new Line(m_startPoint,m_endPoint);
l1->SetDrawLineSort(m_dlsDrawLineSort);
l1->SetPenColor(m_lPenColor);
Line *l2 = new Line(m_startPoint,point);
l2->SetDrawLineSort(m_dlsDrawLineSort);
l2->SetPenColor(m_lPenColor);
l1->Draw(pDC);
l2->Draw(pDC);
Circle *c1 = new Circle(m_startPoint,Distance(m_startPoint,m_endPoint));
c1->SetPenColor(m_lPenColor);
c1->Draw(pDC);
Circle *c2 = new Circle(m_startPoint,Distance(m_startPoint,point));
c2->SetPenColor(m_lPenColor);
c2->Draw(pDC);
break;
}
case dsPolyGon:
{//折线
Line *l1 = new Line(m_startPoint,m_endPoint);
l1->SetDrawLineSort(m_dlsDrawLineSort);
l1->SetPenColor(m_lPenColor);
Line *l2 = new Line(m_startPoint,point);
l2->SetDrawLineSort(m_dlsDrawLineSort);
l2->SetPenColor(m_lPenColor);
l1->Draw(pDC);
l2->Draw(pDC);
break;
}
}
m_endPoint=point;//记录下终点,时刻刷新最后的点
ReleaseDC(pDC);
CView::OnMouseMove(nFlags, point);
}
void CMyDrawView::OnLButtonUp(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
m_bIsMoseDown=FALSE;//鼠标未按下
if(m_dsDrawSort==dsNULL)
return;
CDC *pDC=GetDC();
Line lTemp;
switch(m_dsDrawSort)
{
case dsLine:
case dsPolyGon:
{//画直线或折线
Line *pL1 = new Line(m_startPoint,point);
pL1->SetDrawLineSort(m_dlsDrawLineSort);
pL1->SetPenColor(m_lPenColor);
pL1->Draw(pDC);
lTemp.SetStartPoint(m_startPoint);//设置起点
lTemp.SetEndPoint(point);//设置终点
lTemp.SetDrawLineSort(m_dlsDrawLineSort);//设置画直线方式
lTemp.SetPenColor(m_lPenColor);//设置画笔颜色
m_listAllLines.push_back(lTemp);//保存此直线
if(m_dsDrawSort==dsPolyGon)
{
m_startPoint = point;//把鼠标up的那一点作为新的起点
if(!m_bIsFirstDone)
{//第一条边完成
m_bIsFirstDone=TRUE;
}
}
SetCursor(m_hDLCursor);
break;
}
case dsCircle:
{//画圆
Circle cTemp;
double radius = Distance(m_startPoint,point);//计算半径大小
Circle *pC1 = new Circle(m_startPoint,radius);
pC1->SetPenColor(m_lPenColor);
pC1->Draw(pDC);
cTemp.SetRadis(radius);//设置半径
cTemp.SetMidPoint(m_startPoint);//设置圆心
cTemp.SetPenColor(m_lPenColor);//设置画笔颜色
m_listAllCircles.push_back(cTemp);//保存此圆
pDC->SetROP2(R2_NOTXORPEN);//Pixel is the inverse of the R2_XORPEN color (final pixel = NOT(pen XOR screen pixel)).
Line *pL1 = new Line(m_startPoint,point);
pL1->SetPenColor(m_lPenColor);
pL1->Draw(pDC);
SetCursor(m_hDCCursor);
break;
}
}
ReleaseDC(pDC);
CView::OnLButtonUp(nFlags, point);
}
void CMyDrawView::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
m_bIsMoseDown=TRUE;//鼠标按下了
if(m_dsDrawSort==dsNULL)//画图类型未选择
return;
CDC *pDC=GetDC();
pDC->SetROP2(R2_NOTXORPEN);
Line lTemp;
if(m_dsDrawSort==dsPolyGon && m_bIsFirstDone)
{
Line *pL1 = new Line(m_startPoint,point);
pL1->Draw(pDC);
lTemp.SetStartPoint(m_startPoint);
lTemp.SetEndPoint(point);
m_listAllLines.push_back(lTemp);
}
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2007/07/29/835394.html，如需转载请自行联系原作者
