/// <summary>
/// 列表滚动
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void HomePage_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
if (_scrollView.VerticalOffset > 220)
{
if (_itemsPanel != null)
{
_viewModel.Title = HomeHelper.DateStringFormat((listStories.Items[_itemsPanel.FirstVisibleIndex] as Story).Date);
}
}
else
{
_viewModel.Title = "首页";
}
}
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void Page_Loaded(object sender, RoutedEventArgs e)
{
List <ScrollViewer> list = new List <ScrollViewer>();
HomeHelper.FindChildren <ScrollViewer>(list, listStories); //先找到ScrollViewer 注册ViewChanged事件
if (list.Count > 0)
{
_scrollView = list[0];
_scrollView.ViewChanged += HomePage_ViewChanged;
}
List <ItemsStackPanel> list2 = new List <ItemsStackPanel>();
HomeHelper.FindChildren <ItemsStackPanel>(list2, listStories); //找到ItemStackPanel 它包含FirstVisibleIndex属性
if (list.Count > 0)
{
_itemsPanel = list2[0];
}
}
