如何在WPF上从拖动源拖放到鼠标上绘制一条线？

// 在拖动源上注册事件
private void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    // 开始拖动操作
    DragDrop.DoDragDrop(DragSource, "拖动的数据", DragDropEffects.Copy);
}

private void DragSource_PreviewMouseMove(object sender, MouseEventArgs e)
{
    // 检查鼠标左键是否按下，并且拖动操作已经开始
    if (e.LeftButton == MouseButtonState.Pressed && DragDrop.PreviewDragOver != null)
    {
        // 获取鼠标当前位置
        Point currentPosition = e.GetPosition(DragSource);

        // 找到鼠标下方的元素
        var hitResults = VisualTreeHelper.FindElementsInHostCoordinates(currentPosition, DragSource);

        // 如果找到了目标元素
        if (hitResults.Count > 0)
        {
            // 创建线条
            Line line = new Line();
            line.Stroke = Brushes.Black;
            line.StrokeThickness = 2;

            // 设置线条的起始点和终止点
            line.X1 = 0;
            line.Y1 = 0;
            line.X2 = currentPosition.X;
            line.Y2 = currentPosition.Y;

            // 将线条添加到目标元素上
            UIElement targetElement = hitResults[0] as UIElement;
            targetElement.Children.Add(line);
        }
    }
}

private void DragSource_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    // 结束拖动操作
    DragDrop.PreviewDragOver = null;

    // 清除绘制的线条
    UIElement targetElement = DragSource.Children[0] as UIElement;
    targetElement.Children.Clear();

    // 执行其他操作
    // ...
}