Bounding box cutting of edges on custom ellipse

I have a custom ellipse code shown bellow. I draw a rubber band using the ellipse setting the width and height using two points, code shown bellow. However when I draw the ellipse the bounding box is cutting of the edges on the sides. I solved this issue before with using actual height and width, but this was in a stand alone application. When I integrated it with the rubber band drawing part, actual height and width don't work anymore, for some reason they don't get updated when I set the width and height. Do you know how can I fix it so that the edges don't get cut off.

 namespace WpfApplication4
{
    class Ellipse2 : Shape
    {
        EllipseGeometry ellipse;
        public static readonly DependencyProperty TextBoxShapeProperty = DependencyProperty.Register("TextBoxShape", typeof(TextBoxShape), typeof(Ellipse2), new FrameworkPropertyMetadata(null));
        public TextBoxShape TextBoxShape
        {
            get { return (TextBoxShape)GetValue(TextBoxShapeProperty); }
            set { SetValue(TextBoxShapeProperty, value); }
        }
        public Ellipse2()
        {
            ellipse = new EllipseGeometry();

            this.Fill = Brushes.Transparent;
            this.Stroke = Brushes.Gray;
            this.StrokeThickness = 3;

        }
        protected override Geometry DefiningGeometry
        {
            get
            {
                TranslateTransform t = new TranslateTransform(Width / 2, Height / 2);
         开发者_如何学JAVA       ellipse.Transform = t;
                ellipse.RadiusX = this.Width / 2;
                ellipse.RadiusY = this.Height / 2;

                return ellipse;
            }
        }
    }
}

     double width = Math.Abs(initMousePoint.X - currMousePoint.X);
     double height = Math.Abs(initMousePoint.Y - currMousePoint.Y);
     double left = Math.Min(initMousePoint.X, currMousePoint.X);
     double top = Math.Min(initMousePoint.Y, currMousePoint.Y);
     rubberBandShape.Width = width;
     rubberBandShape.Height = height;
     Canvas.SetTop(rubberBandShape, top);
     Canvas.SetLeft(rubberBandShape, left);

Try to compensate for the StrokeThickness, like

ellipse.RadiusX = (this.Width / 2) - StrokeThickness / 2;
ellipse.RadiusY = (this.Height / 2) - StrokeThickness / 2;