如何在UWP中删除ListViewItem的破碎背景？

Question

我用一些项目创建了Listview.当我点击一个时,我正在导航到新页面.当我按下时,我将回到旧页面(主菜单页面 - >项目页面 - >通过Frame.GoBack()支持主菜单),我看到所有最后点击的项目都是灰色背景.我试图将背景设置为透明,但它不起作用.

在桌面上此问题不存在,背景为黑色. 我正在Windows 10 RS2和Windows 10 Mobile上测试它最后一个内部构建在L640XL.

列表显示:

<ListView Grid.Row="
          Name="LineSecondTrackListView"
          ItemsSource="{x:Bind _LineSecondTrackBusStops}"
          ContainerContentChanging="SetBusStopViewAttribute"
          ItemTemplate="{StaticResource BusStopListViewStyle}"
          SelectionMode="Single"
          SelectionChanged="LineTrackListView_SelectionChangedAsync">
              <ListView.ItemsPanel>
                  <ItemsPanelTemplate>
                      <ItemsWrapGrid HorizontalAlignment="Center"
                                     Orientation="Horizontal" 
                                     MaximumRowsOrColumns="1"/>
                  </ItemsPanelTemplate>
              </ListView.ItemsPanel>
</ListView>

我是如何支持的:

public static void BackButtonPressed(object sender, BackRequestedEventArgs e)
{
    Frame mainAppFrame = MainFrameHelper.GetMainFrame();
    Type currentPageType = mainAppFrame.CurrentSourcePageType;
    bool goBack = IsGoBackFromPageAllowed(currentPageType);
    if (goBack)
    {
        mainAppFrame.GoBack();
        e.Handled = true;
        return;
    }
    App.Current.Exit();
}

private static bool IsGoBackFromPageAllowed(Type currentPageType)
{
    if (currentPageType == typeof(Pages.Lines.LinesViewPage))
        return true;
    if (currentPageType == typeof(Pages.Lines.LinePage))
        return true;
    if (currentPageType == typeof(Pages.Lines.LineBusStopPage))
        return true;
    return false;
}

如何避免这种影响？

编辑

我试过了

foreach (ListViewItem item in LineSecondTrackListView.Items) 
    VisualStateManager.GoToState(item, "Normal", false); //in the OnNavigatedTo 

它不起作用

edit2 在主菜单页面中,当我点击按钮并返回时,此效果保持不变.所有页面都有NavigationCachePage=Required

EDIT3

ButtonListGridView.InvalidateMeasure();
ButtonListGridView.UpdateLayout();
ButtonListGridView.InvalidateArrange();

其中任何一个都没有解决这个问题.

Answer 1

您可以在这里尝试一些事情。我相信您看到的灰色背景PressedBackground是ListViewItemPresenter.

ListView这很可能是 UWP 中的一个计时错误，当选择/按下中的项目时， PressedBackground/PointerOverBackground显示，同时页面 1被缓存并从中清除，Frame然后可以显示页面 2，但应该发生什么缓存之前的问题是，页面1需要完成指针向上/退出动作才能清除PressedBackground/PointerOverBackground颜色，但它未能做到这一点。

要测试这是否是问题的颜色，您所需要做的就是将以下默认值应用于Style您的ItemContainerStyle,ListView并设置PressedBackground="Transparent"or/and PointerOverBackground="Transparent"。

<Style TargetType="ListViewItem">
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}" />
<Setter Property="TabNavigation" Value="Local"/>
<Setter Property="IsHoldingEnabled" Value="True"/>
<Setter Property="Padding" Value="12,0,12,0"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="MinWidth" Value="{ThemeResource ListViewItemMinWidth}"/>
<Setter Property="MinHeight" Value="{ThemeResource ListViewItemMinHeight}"/>
<Setter Property="Template">
  <Setter.Value>
    <ControlTemplate TargetType="ListViewItem">
      <ListViewItemPresenter
          ContentTransitions="{TemplateBinding ContentTransitions}"
          SelectionCheckMarkVisualEnabled="True"
          CheckBrush="{ThemeResource SystemControlForegroundBaseMediumHighBrush}"
          CheckBoxBrush="{ThemeResource SystemControlForegroundBaseMediumHighBrush}"
          DragBackground="{ThemeResource ListViewItemDragBackgroundThemeBrush}"
          DragForeground="{ThemeResource ListViewItemDragForegroundThemeBrush}"
          FocusBorderBrush="{ThemeResource SystemControlForegroundAltHighBrush}"
          FocusSecondaryBorderBrush="{ThemeResource SystemControlForegroundBaseHighBrush}"
          PlaceholderBackground="{ThemeResource ListViewItemPlaceholderBackgroundThemeBrush}"
          PointerOverBackground="Transparent"
          PointerOverForeground="{ThemeResource SystemControlHighlightAltBaseHighBrush}"
          SelectedBackground="{ThemeResource SystemControlHighlightListAccentLowBrush}"
          SelectedForeground="{ThemeResource SystemControlHighlightAltBaseHighBrush}"
          SelectedPointerOverBackground="{ThemeResource SystemControlHighlightListAccentMediumBrush}"
          PressedBackground="Transparent"
          SelectedPressedBackground="{ThemeResource SystemControlHighlightListAccentHighBrush}"
          DisabledOpacity="{ThemeResource ListViewItemDisabledThemeOpacity}"
          DragOpacity="{ThemeResource ListViewItemDragThemeOpacity}"
          ReorderHintOffset="{ThemeResource ListViewItemReorderHintThemeOffset}"
          HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
          VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
          ContentMargin="{TemplateBinding Padding}"
          CheckMode="Inline"/>
    </ControlTemplate>
  </Setter.Value>
</Setter>
</Style>

但即使这可能会解决问题，它也会消除有意义的视觉指示。所以让我们尝试一些别的东西 -

在您的LineTrackListView_SelectionChangedAsync方法中，您不是在延迟后立即导航，而是首先取消选择该项目，给它相同的延迟时间以完成取消选择操作，然后进行导航。您需要有一个标志来避免通过更新SelectedItem.

private bool _isWorking;

private async void LineTrackListView_SelectionChangedAsync(object sender, SelectionChangedEventArgs e)
{
    if (_isWorking)
    {
        return;
    }

    _isWorking = true;

    // Removed some of your code here.

    listView.SelectedItem = -1;
    await Task.Delay(100);

    ChangePageToBusPage(selectedBusStopInListView.BusStop, selectedTrack);

    _isWorking = false;
}

我没有 Windows Phone，所以无法真正测试代码，但希望它能给您一个想法。祝你好运！