如何在xamarin窗体中查看Listview是向上还是向下滚动？

public MainPage()
{
    InitializeComponent();

    // 绑定滚动事件处理程序
    listView.Scrolled += ListView_Scrolled;
}

double previousScrollPosition = 0;

private void ListView_Scrolled(object sender, ScrolledEventArgs e)
{
    if (e.ScrollY > previousScrollPosition)
    {
        // 向下滚动
        Console.WriteLine("向下滚动");
    }
    else
    {
        // 向上滚动
        Console.WriteLine("向上滚动");
    }

    previousScrollPosition = e.ScrollY;
}