private void DrawEllipse(WindowsPen pen, WindowsBrush brush,
int nLeftRect, // x-coord of upper-left corner of rectangle
int nTopRect, // y-coord of upper-left corner of rectangle
int nRightRect, // x-coord of lower-right corner of rectangle
int nBottomRect)
{ // y-coord of lower-right corner of rectangle
HandleRef hdc = new HandleRef(this.dc, this.dc.Hdc);
if (pen != null)
{
// 1. Select the pen in the DC
IntUnsafeNativeMethods.SelectObject(hdc, new HandleRef(pen, pen.HPen));
}
if (brush != null)
{
IntUnsafeNativeMethods.SelectObject(hdc, new HandleRef(brush, brush.HBrush));
}
// 2. call the function
IntUnsafeNativeMethods.Ellipse(hdc, nLeftRect, nTopRect, nRightRect, nBottomRect);
}