视口与映射

如下所示，每次更新后根据客户区大小满窗口绘制一个椭圆

void CTstView::OnDraw(CDC* pDC)
{
CTstDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);

CRect rect;
GetClientRect(&rect);
pDC->Rectangle(&rect);

pDC->SetMapMode(MM_ANISOTROPIC);
pDC->SetWindowExt(1700, 760);
pDC->SetWindowOrg(0, 0);
pDC->SetViewportExt(rect.right, rect.bottom);
pDC->SetViewportOrg(0, 0);

pDC->Ellipse(0, 0, 1700, 760);
pDC->MoveTo(0,0);
pDC->LineTo(1700/2, 760/2);
pDC->LineTo(0, 760);
}