c# - Scrollviewer 和操作事件

Question

我有ListView和Grid。我已经ListView's ScrollViewer完成VisualTreeHelper并添加了ViewChanged事件处理程序。在我禁用的事件处理程序中VerticalScrollMode，VerticalScrollBarVisibility如果垂直偏移设置为 0 以执行操作事件。我正在尝试访问操作事件，但它没有触发。请给我建议。

 <Grid ManipulationDelta="Grid_ManipulationDelta">
                <ListView  x:Name="list" >
                    <TextBlock Text="CONTENT"/>
                    <TextBlock Text="CONTENT"/>
                    <TextBlock Text="CONTENT"/>
                    <TextBlock Text="CONTENT"/>
                </ListView>
                </Grid>

private void Grid_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
}

public MainPage()
{
    var content = list.GetChildrenOfType<ScrollViewer>();
    ScrollViewer scrollViewer = content.First() as ScrollViewer; 
    scrollViewer.ViewChanged += Content_ViewChanged;
}

private void Content_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
    if ((sender as ScrollViewer).VerticalOffset == 0)
    {
        (sender as ScrollViewer).VerticalScrollMode = ScrollMode.Disabled;
    }
}