列表框展開選定的項目

Question

我有以下代碼片段（複製並粘貼到kaxaml，xamlpad等嘗試它） 摺疊所有，但選定的項目。但是，當鼠標沒有超過ListBox時，我想要恢復到所有可見的 ，並且我無法使其無法繼續使用代碼。我正在使用IsMouseOver ListBox屬性在ListBox上設置選定的項目屬性以嘗試觸發更新，但沒有運氣。 任何想法？

 

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> 
<Grid> 
     <ListBox 
      Name="lb" 
      Width="100" 
      Height="100" 
      Background="Red" 
      SelectionMode="Single"> 
      <ListBox.ItemsPanel> 
       <ItemsPanelTemplate> 
        <UniformGrid Columns="1"/> 
       </ItemsPanelTemplate> 
      </ListBox.ItemsPanel> 
      <ListBoxItem Background="AliceBlue">Item 1  
      </ListBoxItem> 
      <ListBoxItem Background="Aquamarine">Item 
      </ListBoxItem> 
      <ListBoxItem Background="Azure">Item 
      </ListBoxItem> 
      <ListBox.ItemContainerStyle> 
       <Style TargetType="{x:Type ListBoxItem}"> 
        <Setter Property="Visibility" Value="Visible"/> 
        <Style.Triggers> 
          <MultiDataTrigger> 
           <MultiDataTrigger.Conditions> 
            <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsSelected}" Value="False"/> 
            <Condition Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBox}},Path=SelectedItems.Count}" Value="1"/> 
           </MultiDataTrigger.Conditions> 
           <MultiDataTrigger.EnterActions> 
            <BeginStoryboard> 
             <Storyboard Duration="0:0:1"> 
               <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility"> 
                <DiscreteObjectKeyFrame KeyTime="0:0:1" Value="{x:Static Visibility.Collapsed}"/> 
               </ObjectAnimationUsingKeyFrames> 
               <DoubleAnimation Duration="0:0:1" Storyboard.TargetProperty="Opacity" To="0"/> 
             </Storyboard> 
            </BeginStoryboard> 
           </MultiDataTrigger.EnterActions> 
          </MultiDataTrigger> 
          <MultiDataTrigger> 
           <MultiDataTrigger.Conditions> 
            <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsSelected}" Value="True"/> 
            <Condition Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBox}},Path=SelectedItems.Count}" Value="1"/> 
           </MultiDataTrigger.Conditions> 
           <MultiDataTrigger.EnterActions> 
            <BeginStoryboard> 
             <Storyboard Duration="0:0:0"> 
               <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility"> 
                <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{x:Static Visibility.Visible}"/> 
               </ObjectAnimationUsingKeyFrames> 
               <DoubleAnimation Duration="0:0:0" Storyboard.TargetProperty="Opacity" To="1"/> 
             </Storyboard> 
            </BeginStoryboard> 
           </MultiDataTrigger.EnterActions> 
          </MultiDataTrigger> 
        </Style.Triggers> 
       </Style> 
      </ListBox.ItemContainerStyle> 
      <ListBox.Style> 
       <Style> 
        <Style.Triggers> 
          <Trigger Property="ListBox.IsMouseOver" Value="False"> 
           <Setter Property="ListBox.SelectedItem" Value="{x:Null}"/> 
           <Setter Property="ListBoxItem.IsSelected" Value="False"/> 
           <Setter Property="ListBox.SelectedIndex" Value="-1"/> 
          </Trigger> 
          <EventTrigger RoutedEvent="Mouse.MouseLeave"> 
           <BeginStoryboard> 
            <Storyboard> 
             <Int32Animation Duration="0:0:0" Storyboard.TargetProperty="SelectedIndex" To="-1"/> 
            </Storyboard> 
           </BeginStoryboard> 
          </EventTrigger> 
        </Style.Triggers> 
       </Style> 
      </ListBox.Style> 
     </ListBox> 
</Grid> 
</Page> 

Answer 1

移動你的風格，以資源和應用它當鼠標移動到ListBox.`

<Page.Resources> 
    <Style x:Key="CustomStyle" TargetType="{x:Type ListBoxItem}"> 
     <Style.Triggers> 
      <MultiDataTrigger> 
       <MultiDataTrigger.Conditions> 
        <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsSelected}" Value="False"/> 
        <Condition Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBox}},Path=SelectedItems.Count}" Value="1"/> 
       </MultiDataTrigger.Conditions> 
       <MultiDataTrigger.EnterActions> 
        <BeginStoryboard> 
         <Storyboard Duration="0:0:1"> 
          <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility"> 
           <DiscreteObjectKeyFrame KeyTime="0:0:1" Value="{x:Static Visibility.Collapsed}"/> 
          </ObjectAnimationUsingKeyFrames> 
          <DoubleAnimation Duration="0:0:1" Storyboard.TargetProperty="Opacity" To="0"/> 
         </Storyboard> 
        </BeginStoryboard> 
       </MultiDataTrigger.EnterActions> 
       <MultiDataTrigger.ExitActions> 
        <BeginStoryboard> 
         <Storyboard Duration="0:0:0"> 
          <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility"> 
           <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{x:Static Visibility.Visible}"/> 
          </ObjectAnimationUsingKeyFrames> 
          <DoubleAnimation Duration="0:0:0" Storyboard.TargetProperty="Opacity" To="1"/> 
         </Storyboard> 
        </BeginStoryboard> 
       </MultiDataTrigger.ExitActions> 
      </MultiDataTrigger> 
     </Style.Triggers> 
    </Style> 
</Page.Resources> 

<Grid> 
    <ListBox 
     Name="lb" 
     Width="100" 
     Height="100" 
     Background="Red" 
     SelectionMode="Single"> 
     <ListBox.ItemsPanel> 
      <ItemsPanelTemplate> 
       <UniformGrid Columns="1"/> 
      </ItemsPanelTemplate> 
     </ListBox.ItemsPanel> 
     <ListBoxItem Background="AliceBlue">Item 1 
     </ListBoxItem> 
     <ListBoxItem Background="Aquamarine">Item 
     </ListBoxItem> 
     <ListBoxItem Background="Azure">Item 
     </ListBoxItem> 
     <ListBox.Style> 
      <Style> 
       <Style.Triggers> 
        <Trigger Property="ListBox.IsMouseOver" Value="True"> 
         <Setter 
          Property="ListBox.ItemContainerStyle" 
          Value="{StaticResource CustomStyle}"/> 
        </Trigger> 
       </Style.Triggers> 
      </Style> 
     </ListBox.Style> 
    </ListBox> 
</Grid> 

` 還要注意MultiDataTrigger.ExitActions的使用，這些是在觸發器對象變爲非活動狀態時應用的操作。