Question

我在列表视图中有以下数据模板和一些窃听事件（下面的XAML）。为了隐藏/显示数据模板中某个项目的可见性，我使用下面的逻辑（确定我的原始源）来标识列表视图中的哪个控件调用了一个事件。我看到的这种方法的问题是，即使对数据模板进行了最小的更改，我也正在更改事件逻辑以确定合适的孩子。有没有可以使用的高效逻辑，这样，每次我更改布局时，我都不必触摸后面的代码？

XAML

  <DataTemplate x:DataType="filter:FilterCategory">
     <!--<RelativePanel>-->
     <Grid Name="FilterHeaders">
        <Grid.ColumnDefinitions>
           <ColumnDefinition Width="4*"/>
           <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
           <RowDefinition Height="*"/>
           <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <TextBlock Name="Header" FontSize="13" FontWeight="Bold" Margin="20,10,0,0" Text="{x:Bind NameAlias}" Grid.Column="0"/>
        <RelativePanel Grid.Column="1">
           <TextBlock Name="DownArrow" Text="&#xE70D;" FontFamily="Segoe MDL2 Assets" FontSize="8" 
                    Visibility="{x:Bind IsCollapsed}" Grid.Column="1" Tapped="DownArrow_Tapped" 
                    RelativePanel.AlignRightWithPanel="True" HorizontalAlignment="Right" Margin="0,10,0,0"/>
           <TextBlock Name="UpArrow" Text="&#xE70E;" FontFamily="Segoe MDL2 Assets" FontSize="8" 
                    Visibility="{x:Bind IsExpand}" RelativePanel.AlignRightWithPanel="True" Tapped="UpArrow_Tapped" 
                    VerticalAlignment="Center" HorizontalAlignment="Right" Margin="0,10,0,0"/>
        </RelativePanel>
        <Grid Grid.Row="1" Grid.ColumnSpan="2" Visibility="{Binding ElementName=UpArrow,Path=Visibility}">
           <ListView SelectionMode="None" ItemsSource="{x:Bind FilterCategoryItems}" ScrollViewer.VerticalScrollMode="Enabled">
              <ListView.ItemContainerTransitions>
                 <TransitionCollection/>
              </ListView.ItemContainerTransitions>
              <ListView.ItemContainerStyle>
                 <Style TargetType="ListViewItem">
                    <Setter Property="HorizontalAlignment" Value="Left"/>
                    <Setter Property="HorizontalContentAlignment" Value="Left" />
                    <Setter Property="FontSize" Value="13"/>
                    <Setter Property="MinHeight" Value="0"/>
                    <Setter Property="Margin" Value="5,0,0,0"/>
                 </Style>
              </ListView.ItemContainerStyle>
              <ListView.ItemTemplate>
                 <DataTemplate x:DataType="filter:FilterCategoryItem">
                    <Grid>
                       <Grid.ColumnDefinitions>
                          <ColumnDefinition Width="30" />
                          <ColumnDefinition Width="Auto"/>
                       </Grid.ColumnDefinitions>
                       <CheckBox x:Name="FilterCheckBoxTask" Style="{StaticResource CheckBoxStylePlainView}" IsThreeState="False" 
                                Opacity="0.2" MinWidth="10"/>
                       <TextBlock Grid.Column="1" Text="{x:Bind NameAlias}"/>
                    </Grid>
                 </DataTemplate>
              </ListView.ItemTemplate>
              <!--<ListView.FooterTemplate>
                                   <DataTemplate>
                                      <Grid>
                                         <Button x:Name="LoadMore" Tag="{x:Bind Name}" Content="Load More" Click="LoadMore_Click" Visibility="Visible"/>
                                      </Grid>
                                   </DataTemplate>
                                </ListView.FooterTemplate>-->
           </ListView>
           <loading:LoadingControl Name="LoadingControl" IsShowGrid="{Binding IsShowResultGrid,Mode=TwoWay}" 
                                   IsShowProgressRing="{Binding IsShowProgressRing,Mode=TwoWay}" 
                                   ShowDisplayMessage="{Binding DisplayMessage,Mode=TwoWay}" />
        </Grid>
     </Grid>
  </DataTemplate>

背后的代码

private void DownArrow_Tapped(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs e)
        {
            if (e.OriginalSource is TextBlock textBlock)
            {
                textBlock.Visibility = Visibility.Collapsed;
                if (textBlock.Parent is Grid grid)
                {
                    if (grid.Children[2] is TextBlock textBlck)
                        textBlck.Visibility = Visibility.Visible;
                }
            }
        }

        private void UpArrow_Tapped(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs e)
        {
            if (e.OriginalSource is TextBlock textBlock)
            {
                textBlock.Visibility = Visibility.Collapsed;
                if (textBlock.Parent is Grid grid)
                {
                    if (grid.Children[1] is TextBlock textBlck)
                        textBlck.Visibility = Visibility.Visible;
                }
            }
        }

Answer 1

您需要通过以下方式使用行为SDK：XamlBehaviors

安装nuget软件包后，可以使用以下代码：

 <TextBlock x:Name="mytext" Text="1" Grid.Column="0">
                <Interactivity:Interaction.Behaviors>
                    <Interactions:EventTriggerBehavior EventName="Tapped">
                        <Interactions:ChangePropertyAction TargetObject="{Binding ElementName=mytext}" PropertyName="Visibility" Value="Collapsed"/>
                    </Interactions:EventTriggerBehavior>
                </Interactivity:Interaction.Behaviors>
            </TextBlock>

有关更多详细信息，您可以参考此doc。

我需要承认这可能无法满足您的所有需求。实际上，您不知道以下行：grid.Children是TextBlock textBlck。我将在有时间的时候考虑使用绑定和转换器。但是在我看来，行为SDK是您的一个方向。请先看看。

如何有效地处理从Listview的数据模板中生成的事件

1 个答案: