在Code中使用GeometryGroup创建combineshape

我的代码需要一些帮助 . combineShape.Freeze（）函数看起来效果不佳 .

在这种情况下，我有两个单选按钮，名为rbtPoint和rbtLine . 当我单击rbtPoint并单击画布时，它将创建一个点，现在我必须在画布中创建2个点（ellipse1，ellipse2），在此步骤中我已经能够在画布周围拖动Point（ellipse1或elipse2） . 然后当我点击rbtLine然后点击第一个点（ellipse1）它会将点的颜色从红色变为蓝色，然后当我再次点击第二个点（ellipse2）时，它也会将颜色变为红色，它将会创建从ellipse1到ellipse2的连接蓝线 . 之后，使用GeometryGroup（）函数将线和2个点组合成1个形状 . 我看到了这个链接的代码：

http://stackoverflow.com/questions/16417950/combining-linegeometry-with-ellipsegeometry-in-code-not-xaml

这是我创建函数的代码：

private void myCanvas_MouseDown(object sender, MouseButtonEventArgs e)
        {
            mouseDown  = true;
            initialPoint = e.GetPosition(sender as IInputElement);

            if (rbtPoint.IsChecked == true)
            {
                if (e.OriginalSource is Ellipse)
                {
                    captured = true;
                    shapePoint = e.GetPosition(sender as IInputElement);
                    clickedEllipse = (Ellipse)e.OriginalSource;
                    uielement = (UIElement)e.OriginalSource;
                }
                else
                {
                    shapeEllipse = new Ellipse();
                    (shapeEllipse as Ellipse).Width = 30;
                    (shapeEllipse as Ellipse).Height = 30;
                    (shapeEllipse as Ellipse).StrokeThickness = 5;
                    (shapeEllipse as Ellipse).Fill = Brushes.Red;
                    Canvas.SetLeft(shapeEllipse, initialPoint.X);
                    Canvas.SetTop(shapeEllipse, initialPoint.Y);
                    myCanvas.Children.Add(shapeEllipse);
                }
            }
        }

private void myCanvas_MouseUp(object sender, MouseButtonEventArgs e)
        {
            Mouse.Capture(null);
            captured = false;
            mouseDown = false;
            if (rbtLine.IsChecked == true)
            {
                if (e.OriginalSource is Ellipse)
                {
                    captured = true;
                    initialPoint = e.GetPosition(sender as IInputElement);
                    clickedEllipse = (Ellipse)e.OriginalSource;
                    uielement = (UIElement)e.OriginalSource;
                    poin = e.MouseDevice.GetPosition(uielement);
                    clickedEllipse.Fill = Brushes.Blue;
                    if (firstpoint.X != 0 && firstpoint.Y != 0)
                    {
                        lineEndPoint = initialPoint;
                    }
                    else
                    {
                        firstpoint = initialPoint;
                    }
                }

                if (lineEndPoint.X != 0 && lineEndPoint.Y != 0)
                {
                    Point p = e.GetPosition(sender as IInputElement);
                    shapeLine = new Line();
                    (shapeLine as Line).X1 = firstpoint.X;
                    (shapeLine as Line).Y1 = firstpoint.Y;
                    (shapeLine as Line).X2 = lineEndPoint.X;
                    (shapeLine as Line).Y2 = lineEndPoint.Y;
                    (shapeLine as Line).Stroke = Brushes.Blue;
                    (shapeLine as Line).StrokeThickness = 5;
                    //(shape as Line).Fill = Brushes.Blue;
                    //Canvas.SetLeft(shape, firstpoint.X);
                    //Canvas.SetTop(shape, firstpoint.Y);
                    myCanvas.Children.Add(shapeLine);
                    lineCreated = true;

                    var ellipse1 = new EllipseGeometry(firstpoint, firstpoint.X, firstpoint.Y);
                    var ellipse2 = new EllipseGeometry(lineEndPoint, lineEndPoint.X, lineEndPoint.Y);
                    var line = new LineGeometry(this.firstpoint, this.lineEndPoint);

                    GeometryGroup combinedShape = new GeometryGroup();
                    combinedShape.Children.Add(ellipse1);
                    combinedShape.Children.Add(ellipse2);
                    combinedShape.Children.Add(line);

                    combinedShape.Freeze();
                }

            }
        }

运行combinedShape.Freeze（）函数后，当我再次单击其中一个Point并拖动它时，它只移动点击的点，而不是鼠标移动后的其他点和线 .

如何解决这个问题呢？我发现很多相关的文章，但大多数文章他们在XAML中执行代码而不是代码 . 或者还有其他方法可以解决这个问题吗？我需要建议这个问题，

感谢您的帮助，代码大师......

Fikri