C# 如何在画布上绘制一个可拖动的矩形？

我有这三个函数来触发事件。我已经有了一个静态版本的需求，但我需要一个动态版本的需求

我已经在WPF中制作了一个名为“canvasPreview”的画布，我想将矩形（目前在静态版本中，我使用的是椭圆）添加到画布中，它必须可以通过上述函数拖动。它已经在工作了，但必须是动态的

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我希望你能帮助我，提前谢谢你

我相信此示例代码将对您有所帮助

XAML：

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如果不是动态的，它是如何工作的？你说它必须是动态的到底是什么意思？这个形状不会被拖走吗？对不起。静态版本正在工作，我的意思是，在WPF中创建的椭圆是可拖动的，但是当我尝试生成椭圆（应该是矩形）时，它不可拖动，但是调用了函数。函数在画布中吗？如果插入断点并开始尝试拖动矩形，“源”在MouseLeftButtonDown中设置为什么？MouseDragElementBehavior呢？来自混合交互行为？[谢谢！问题解决了！是SetLeft和SetTop属性。祝您好运，祝您成功。

    bool captured = false;
    double x_shape, x_canvas, y_shape, y_canvas;
    UIElement source = null;

    private void MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        source = (UIElement)sender;
        Mouse.Capture(source);
        captured = true;
        x_shape = Canvas.GetLeft(source);
        x_canvas = e.GetPosition(canvasPreview).X;
        y_shape = Canvas.GetTop(source);
        y_canvas = e.GetPosition(canvasPreview).Y;
    }

    private void MouseMove(object sender, MouseEventArgs e)
    {
        //MessageBox.Show("test");
        if (captured)
        {
            double x = e.GetPosition(canvasPreview).X;
            double y = e.GetPosition(canvasPreview).Y;
            x_shape += x - x_canvas;
            Canvas.SetLeft(source, x_shape);
            x_canvas = x;
            y_shape += y - y_canvas;
            Canvas.SetTop(source, y_shape);
            y_canvas = y;
        }
    }

    private void MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        Mouse.Capture(null);
        captured = false;
    }

<Grid Margin="12">
    <Grid.RowDefinitions>
        <RowDefinition Height="auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <StackPanel Grid.Row="0" Orientation="Horizontal">
        <Button x:Name="addRectangleButton" Content="Add Rectngle" Click="addRectangleButton_Click"/>
    </StackPanel>

    <Canvas Grid.Row="1" x:Name="canvas" Margin="0,12,0,0">
        <Rectangle x:Name="rectangle" Width="100" Height="50" Fill="RoyalBlue" MouseDown="rectangle_MouseDown" MouseMove="rectangle_MouseMove" MouseUp="rectangle_MouseUp" Canvas.Left="0" Canvas.Top="0"/>
    </Canvas>
</Grid>

    bool drag = false;
    Point startPoint;

    public MainWindow()
    {
        InitializeComponent();
    }

    // this creates and adds rectangles dynamically
    private void addRectangleButton_Click(object sender, RoutedEventArgs e)
    {
        // create new Rectangle
        Rectangle rectangle = new Rectangle();
        // assign properties
        rectangle.Width = 100;
        rectangle.Height = 50;
        rectangle.Fill = new SolidColorBrush(Colors.RoyalBlue);
        // assign handlers
        rectangle.MouseDown += rectangle_MouseDown;
        rectangle.MouseMove += rectangle_MouseMove;
        rectangle.MouseUp += rectangle_MouseUp;
        // set default position
        Canvas.SetLeft(rectangle, 0);
        Canvas.SetTop(rectangle, 0);
        // add it to canvas
        canvas.Children.Add(rectangle);
    }

    private void rectangle_MouseDown(object sender, MouseButtonEventArgs e)
    {
        // start dragging
        drag = true;
        // save start point of dragging
        startPoint = Mouse.GetPosition(canvas);
    }

    private void rectangle_MouseMove(object sender, MouseEventArgs e)
    {
        // if dragging, then adjust rectangle position based on mouse movement
        if (drag)
        {
            Rectangle draggedRectangle = sender as Rectangle;
            Point newPoint = Mouse.GetPosition(canvas);
            double left = Canvas.GetLeft(draggedRectangle);
            double top = Canvas.GetTop(draggedRectangle);
            Canvas.SetLeft(draggedRectangle, left + (newPoint.X - startPoint.X));
            Canvas.SetTop(draggedRectangle, top + (newPoint.Y - startPoint.Y));

            startPoint = newPoint;
        }
    }

    private void rectangle_MouseUp(object sender, MouseButtonEventArgs e)
    {
        // stop dragging
        drag = false;
    }