【WPF】请帮忙实现，在canvas中通过鼠标框选区域，然后弹出窗体，配置相关参数后在canvas添加对应控件，控件与框选的矩形通过连线表示有关联关系

好的，让我来帮你实现这个功能。以下是实现步骤：

1. 在Canvas上添加PreviewMouseLeftButtonDown、PreviewMouseMove、PreviewMouseLeftButtonUp事件处理器。

2. 在PreviewMouseLeftButtonDown事件处理器中，记录起始点坐标，并创建一个Rectangle控件用于表示选框。将选框添加到Canvas上，并设置其起始位置。

3. 在PreviewMouseMove事件处理器中，检查是否按下鼠标左键，如果是则更新选框的位置和大小。

4. 在PreviewMouseLeftButtonUp事件处理器中，结束选框操作，计算选框的位置和大小，并弹出窗体，让用户进行参数配置。

5. 在窗体中添加确定按钮，当用户单击确定按钮后，在Canvas上添加对应控件，并设置控件的位置和大小。

6. 在控件上添加鼠标事件处理器，实现控件的拖拽功能。

7. 在控件上添加连线，表示控件与选框的关联关系。

以下是代码示例：

private Point startPoint;
private Rectangle selectRect;

private void canvas_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    startPoint = e.GetPosition(canvas);
    selectRect = new Rectangle
    {
        Stroke = Brushes.Red,
        StrokeThickness = 1,
        Opacity = 0.5
    };
    Canvas.SetLeft(selectRect, startPoint.X);
    Canvas.SetTop(selectRect, startPoint.Y);
    canvas.Children.Add(selectRect);
}

private void canvas_PreviewMouseMove(object sender, MouseEventArgs e)
{
    if (e.LeftButton == MouseButtonState.Pressed && selectRect != null)
    {
        double left = Math.Min(e.GetPosition(canvas).X, startPoint.X);
        double top = Math.Min(e.GetPosition(canvas).Y, startPoint.Y);
        double width = Math.Abs(e.GetPosition(canvas).X - startPoint.X);
        double height = Math.Abs(e.GetPosition(canvas).Y - startPoint.Y);
        selectRect.Width = width;
        selectRect.Height = height;
        Canvas.SetLeft(selectRect, left);
        Canvas.SetTop(selectRect, top);
    }
}

private void canvas_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    if (selectRect != null)
    {
        double left = Math.Min(e.GetPosition(canvas).X, startPoint.X);
        double top = Math.Min(e.GetPosition(canvas).Y, startPoint.Y);
        double width = Math.Abs(e.GetPosition(canvas).X - startPoint.X);
        double height = Math.Abs(e.GetPosition(canvas).Y - startPoint.Y);
        selectRect.Width = width;
        selectRect.Height = height;
        Canvas.SetLeft(selectRect, left);
        Canvas.SetTop(selectRect, top);

        // 弹出窗体，让用户进行参数配置
        ConfigWindow configWindow = new ConfigWindow();
        if (configWindow.ShowDialog() == true)
        {
            // 创建对应控件，并设置位置和大小
            Control control = new Control();
            control.Width = configWindow.ControlWidth;
            control.Height = configWindow.ControlHeight;
            Canvas.SetLeft(control, left);
            Canvas.SetTop(control, top);

            // 添加控件到Canvas上
            canvas.Children.Add(control);

            // 添加控件的拖拽事件处理器
            control.PreviewMouseLeftButtonDown += control_PreviewMouseLeftButtonDown;
            control.PreviewMouseMove += control_PreviewMouseMove;
            control.PreviewMouseLeftButtonUp += control_PreviewMouseLeftButtonUp;

            // 添加控件的连线
            Line line = new Line
            {
                X1 = Canvas.GetLeft(selectRect) + selectRect.Width / 2,
                Y1 = Canvas.GetTop(selectRect) + selectRect.Height / 2,
                X2 = Canvas.GetLeft(control) + control.Width / 2,
                Y2 = Canvas.GetTop(control) + control.Height / 2,
                Stroke = Brushes.Black,
                StrokeThickness = 1,
                Opacity = 0.5
            };
            canvas.Children.Add(line);
        }
        canvas.Children.Remove(selectRect);
        selectRect = null;
    }
}

private bool isDragging = false;
private Point dragStartPoint;

private void control_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    isDragging = true;
    dragStartPoint = e.GetPosition(canvas);
    e.Handled = true;
}

private void control_PreviewMouseMove(object sender, MouseEventArgs e)
{
    if (isDragging && e.LeftButton == MouseButtonState.Pressed)
    {
        Control control = sender as Control;
        double left = Canvas.GetLeft(control);
        double top = Canvas.GetTop(control);
        left += e.GetPosition(canvas).X - dragStartPoint.X;
        top += e.GetPosition(canvas).Y - dragStartPoint.Y;
        Canvas.SetLeft(control, left);
        Canvas.SetTop(control, top);
        dragStartPoint = e.GetPosition(canvas);
        e.Handled = true;
    }
}

private void control_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    isDragging = false;
    e.Handled = true;
}

这样，就可以实现在Canvas中通过鼠标框选区域，然后弹出窗体，配置相关参数后在Canvas添加对应控件，控件与框选的矩形通过连线表示有关联关系的功能了。