void CSinusoidView::OnDraw(CDC* pDC)
{
CSinusoidDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here
//建立画笔
CPen cpen,pen;
pen.CreatePen(PS_SOLID,4,RGB(0,0,0));
cpen.CreatePen(PS_SOLID,2,RGB(0,0,255));
pDC->SelectObject(&cpen);
//指定原点
pDC->SetViewportOrg(100,245);
pDC->SetTextColor(RGB(255,0,0));
//绘制横坐标
CString sPIText[]={"-1/2π","","1/2π","π","3/2π","2π","5/2π","3π","7/2π","4π","9/2π","5π"};
for(int n=-1,nTmp=0;nTmp<=660;n++,nTmp+=60)
{
pDC->LineTo(60*n,0);
pDC->LineTo(60*n,-5);
pDC->MoveTo(60*n,0);
pDC->TextOut(60*n-sPIText[n+1].GetLength()*3,16,sPIText[n+1]);
}
pDC->MoveTo(0,0);
CString sTmp;
//绘制纵坐标
for(n=-4,nTmp=0;nTmp<=180;n++,nTmp=60*n)
{
pDC->LineTo(0,60*n);
pDC->LineTo(5,60*n);
pDC->MoveTo(0,60*n);
sTmp.Format("%d",-n);
pDC->TextOut(10,60*n,sTmp);
}
double y,radian;
pDC->SelectObject(&pen);
for(int x=-60;x<600;x++)
{
//弧度=X坐标/曲线宽度*角系数*π
//Y坐标=振幅*曲线宽度*sin(弧度)
radian =x/((double)60*2)*PI;
y=sin(radian)*2*60;
pDC->MoveTo((int)x,(int)y);
pDC->LineTo((int)x,(int)y);
}
cpen.DeleteObject();
pen.DeleteObject();
}
使用
MovoTo指定画笔位置
LineTo用指定画笔画一条线,从当前位位置画到一个指定的位置
ondraw和onpaint的区别:
onpaint是WM_PAINT消息处理函数,ondraw是一个虚函数只存在于document/view框架里。
在document/view框架里,当窗口显示有变化时系统自动调用onpaint,在onpaint里调用的ondraw。
refer to http://www.codeguru.com/forum/archive/index.php/t-268550.html
example78
http://download.csdn.net/detail/luck_good/3788016