我在ScrollViewer中有一个Grid。我为网格设置了一个长高度。
动态地，我添加一个Canvas到我的网格，并在其中添加2个矩形。鼠标缩放事件正在工作，但当我启动应用程序并向下滚动到2个框的末尾，我试图用鼠标缩放时，scrollviewer会上升到其起始位置。我不想禁用它，我希望它继续显示，但不向上移动。

• MainWindow.xaml

<ScrollViewer VerticalScrollBarVisibility="Visible" HorizontalScrollBarVisibility="Visible" Name="sv">
    <Grid Name="myGrid">
        <Grid.RowDefinitions>
            <RowDefinition Height="50" />
            <RowDefinition Height="5000" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="330" />
        </Grid.ColumnDefinitions>
    </Grid>
</ScrollViewer>

• MainWindow.xaml.cs

public partial class MainWindow : Window
{
    double currentZoom = 0;
    ScaleTransform scaleTransform;
    TransformGroup transformGroup;

    public MainWindow()
    {
        InitializeComponent();
        scaleTransform = new ScaleTransform();
        transformGroup = new TransformGroup();

        transformGroup.Children.Add(scaleTransform);
        begin();
    }
    private void begin()
    {
        Canvas canvas = new Canvas();
        Rectangle rectangle1 = new Rectangle
        {
            Width = 300,
            Height = 600,
            Fill = new SolidColorBrush(Color.FromRgb(255, 255, 255)),
            StrokeThickness = 2,
            Stroke = Brushes.Black
        };
        Canvas.SetLeft(rectangle1, 100);
        Canvas.SetTop(rectangle1, 100);
        canvas.Children.Add(rectangle1);

        Rectangle rectangle2 = new Rectangle
        {
            Width = 300,
            Height = 600,
            Fill = new SolidColorBrush(Color.FromRgb(255, 255, 255)),
            StrokeThickness = 2,
            Stroke = Brushes.Black
        };
        Canvas.SetLeft(rectangle2, 200);
        Canvas.SetTop(rectangle2, 200);
        canvas.Children.Add(rectangle2);

        myGrid.Children.Add(canvas);
        myGrid.RenderTransform = transformGroup;
        myGrid.MouseWheel += (sender, e) => wheelEvent(sender, e);
    }
    private void wheelEvent(object sender, MouseWheelEventArgs e)
    {
        Point position = e.GetPosition(myGrid);

        scaleTransform.CenterX = position.X;
        scaleTransform.CenterY = position.Y;

        var newZoom = e.Delta / 120 / (double)50;
        scaleTransform.ScaleX = 1 + newZoom + currentZoom;
        scaleTransform.ScaleY = 1 + newZoom + currentZoom;
        currentZoom += newZoom;
    }
}