我正在开发
Windows通用手机应用程序.
我有一个列表视图和一个按钮.我想在列表视图中向下滚动时隐藏按钮.
如何捕捉滚动事件？如何访问ListView中的ScrollViewer？
我尝试了几种方法,但似乎没有工作..
我的XAML代码是：
<ListView x:Name="PostListView" Grid.Row="1"
IsItemClickEnabled="True"
ItemTemplate="{StaticResource PostItemTemplate}"
ItemsSource="{Binding Feed}"
ShowsScrollingPlaceholders="False"
ScrollViewer.VerticalScrollBarVisibility="Auto"
ScrollViewer.VerticalScrollMode="Enabled"
IncrementalLoadingTrigger="Edge">
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Setter Property="Padding" Value="0" />
<Setter Property="Margin" Value="0" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<ListViewItemPresenter
SelectedBackground="{StaticResource LightStandardColorBrush}"
SelectedPointerOverBackground="{StaticResource LightStandardColorBrush}"
PressedBackground="{StaticResource LightStandardColorBrush}"
SelectedPressedBackground="{StaticResource LightStandardColorBrush}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="Tapped">
<core:InvokeCommandAction Command="{Binding PostItemTapped}" CommandParameter="{Binding ElementName=PostListView, Path=SelectedItem}"/>
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
</ListView>
最佳答案 你可以用两种方式做
1)您可以在listview中侦听PointerEntered事件
<ListView PointerEntered="PointerEntered" x:Name="PostListView" >
....
</ListView>
private void PointerEntered(object sender, PointerRoutedEventArgs e)
{
listScrollviewer = Scrolling(PostListView);
}
private ScrollViewer Scrolling(DependencyObject depObj)
{
ScrollViewer foundOne = GetScrollViewer(depObj);
if (foundOne != null)
{
// if (foundOne.VerticalOffset == 0)
// //refresh.Visibility = Visibility.Visible;
// else
//refresh.Visibility = Visibility.Collapsed;
foundOne.ViewChanging += foundOne_ViewChanging;
}
return foundOne;
}
public static ScrollViewer GetScrollViewer(DependencyObject depObj)
{
if (depObj is ScrollViewer) return depObj as ScrollViewer;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
var child = VisualTreeHelper.GetChild(depObj, i);
var result = GetScrollViewer(child);
if (result != null) return result;
}
return null;
}
private void foundOne_ViewChanging(object sender, ScrollViewerViewChangingEventArgs e)
{
//YOur logic to hide the button
if (e.NextView.VerticalOffset == 0)
{
}
else
{
//Hide the button
}
}
2)第二种方式是编辑列表视图样式.在那里你会得到滚动查看器
<ListView Style="{StaticResource ListViewStyle1}">
...
</ListView>
<Style x:Key="ListViewStyle1" TargetType="ListView">
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="TabNavigation" Value="Once"/>
<Setter Property="IsSwipeEnabled" Value="True"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Bottom"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled"/>
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.HorizontalScrollMode" Value="Disabled"/>
<Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto"/>
<Setter Property="ScrollViewer.ZoomMode" Value="Disabled"/>
<Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False"/>
<Setter Property="ScrollViewer.BringIntoViewOnFocusChange" Value="True"/>
<Setter Property="ItemContainerTransitions">
<Setter.Value>
<TransitionCollection>
<AddDeleteThemeTransition/>
<ReorderThemeTransition/>
</TransitionCollection>
</Setter.Value>
</Setter>
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<ItemsStackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
<ScrollViewer x:Name="ScrollViewer" AutomationProperties.AccessibilityView="Raw" BringIntoViewOnFocusChange="{TemplateBinding ScrollViewer.BringIntoViewOnFocusChange}" HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}" IsHorizontalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsHorizontalScrollChainingEnabled}" IsVerticalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsVerticalScrollChainingEnabled}" IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" TabNavigation="{TemplateBinding TabNavigation}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}" ZoomMode="{TemplateBinding ScrollViewer.ZoomMode}">
<ItemsPresenter FooterTransitions="{TemplateBinding FooterTransitions}" FooterTemplate="{TemplateBinding FooterTemplate}" Footer="{TemplateBinding Footer}" HeaderTemplate="{TemplateBinding HeaderTemplate}" Header="{TemplateBinding Header}" HeaderTransitions="{TemplateBinding HeaderTransitions}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</ScrollViewer>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
