//绘制光圈CDC* dc = GetDC();int oldrop = dc->GetROP2();dc->SetROP2(R2_XORPEN);
HPEN hpen = CreatePen(PS_SOLID,2,RGB(0,255,0));dc->SelectObject(hpen);dc->SelectObject(GetStockObject(NULL_BRUSH));dc->Ellipse((OriginPos.x-Diameter/2.0),(OriginPos.y-Diameter/2.0),(OriginPos.x+Diameter/2.0),(OriginPos.y+Diameter/2.0));dc->Ellipse((point.x-Diameter/2.0),(point.y-Diameter/2.0),(point.x+Diameter/2.0),(point.y+Diameter/2.0));
OriginPos = point;
dc->SetROP2(oldrop);
::DeleteObject(hpen);::DeleteObject(GetStockObject(NULL_BRUSH));ReleaseDC(dc);
