//Добавить эллипс
public void AddEllipse(Point up, Point down)
{
sCircle circle = new sCircle(GetDeleateContainer(), up, down);
shapelist.Add(circle);
circle.Draw();
SynchronizeImage();
}
//Рисует временный эллипс средствами gdi32
public void TempEllipse(Point a, Point b)
{
IntPtr hdc = NativeMethods.GetDC(cnv.Handle);
sCircle Circle;
Rectangle rect;
NativeMethods.SetROP2(hdc, NativeMethods.R2_NOT);
NativeMethods.SelectObject(hdc, NativeMethods.GetStockObject(NativeMethods.HOLLOW_BRUSH));
if ((oldb.X != int.MinValue) & (oldb.Y != int.MinValue))
{
Circle = new sCircle(GetDeleateContainer(), a, oldb);
rect = Circle.GetRect();
NativeMethods.Ellipse(hdc, rect.X, rect.Y, rect.Width, rect.Height);
}
Circle = new sCircle(GetDeleateContainer(), a, b);
rect = Circle.GetRect();
NativeMethods.Ellipse(hdc, rect.X, rect.Y, rect.Width, rect.Height);
oldb = b;
NativeMethods.ReleaseDC(cnv.Handle, hdc);
}