wpf - 自定义椭圆上边缘的边界框切割

Question

我有一个自定义椭圆代码，如下所示。我使用椭圆绘制橡皮筋，使用两个点设置宽度和高度，代码如下所示。但是，当我绘制椭圆时，边界框正在切割侧面的边缘。我之前使用实际高度和宽度解决了这个问题，但这是在一个独立的应用程序中。当我将它与橡皮筋绘图部分集成时，实际高度和宽度不再起作用，由于某种原因，当我设置宽度和高度时它们没有得到更新。你知道我怎样才能修复它，这样边缘就不会被切断。

 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);
                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);

Answer 1

尝试补偿 StrokeThickness，例如

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