3

我有一个ListView用于显示字段列表的 in wpf；基于属性值，某些字段可以在运行时折叠。它工作正常，除了 ListVIew 不会折叠为 ListViewItem 保留的空间，该空间在运行时折叠。

在此处输入图像描述

我能够在 Snoop 中看到额外的 ListViewItems（具有折叠的可见性），ListView 也会向上移动项目，但它不会调整其高度以移除空白空间！

我可以肯定地说，这是因为VirtualizedStackPanel将 ItemsPanel 更改为 StackPanel 解决了问题。这是相关的ListViewXAML：

<ListView
    x:Class="Wizards.FieldBinderModelListView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Margin="0"
    VerticalAlignment="Top"
    HorizontalContentAlignment="Stretch"
    VerticalContentAlignment="Top"
    Background="White"
    BorderThickness="0"
    Grid.IsSharedSizeScope="True"
    KeyboardNavigation.DirectionalNavigation="Continue"
    Padding="1"
    ScrollViewer.HorizontalScrollBarVisibility="Hidden"
    ScrollViewer.VerticalScrollBarVisibility="Hidden"
    SelectionChanged="ListViewSelectionChanged"
    SelectionMode="Single">
    <ListView.ItemsPanel>
       <ItemsPanelTemplate>
        <!--Works fine with StackPanel but not with VirtualizingStackPanel
          Explicitly added this PanelTemplate to show that it works with            
          StackPanel;ListView uses VirtualizingStackPanel as default panel 
          and causes same problem-->              
        <!--<StackPanel Orientation="Vertical" VerticalAlignment="Top"/>-->
          <VirtualizingStackPanel Orientation="Vertical" 
               VerticalAlignment="Top"/>
       </ItemsPanelTemplate>
    </ListView.ItemsPanel>
    <ListView.ItemContainerStyle>
      <Style TargetType="{x:Type ListViewItem}">
        <Style.Triggers>
            <Trigger Property="IsSelected" Value="True">
                <Setter Property="Foreground" Value="Black" />
            </Trigger>
            <DataTrigger Binding="{Binding Status}"
                         Value="{x:Static local:Status.NotExisting}">
                <!--Hide the fields which are in NotExisting state; 
                  Need a trigger here as Status can be different -->
                <Setter Property="Visibility" Value="Collapsed" />
            </DataTrigger>
        </Style.Triggers>
      </Style>
  </ListView.ItemContainerStyle>
  <ListView.ItemTemplate>
    <DataTemplate DataType="{x:Type View:FieldViewModel}">
       <local:FieldEditor
          Margin="0,2,0,0"
          HorizontalAlignment="Stretch"
          VerticalAlignment="Top"
          HorizontalContentAlignment="Stretch"
          VerticalContentAlignment="Top"
          Padding="0">
          <!--<local:FieldEditor.Style>
              <Style TargetType="{x:Type local:FieldEditor}">
                <Style.Triggers>
                  <DataTrigger
                    Binding="{Binding Status}"
                    Value="{x:Static local:Status.NotExisting}">
                      <Setter Property="Visibility" Value="Collapsed" />
                  </DataTrigger>
                </Style.Triggers>
              </Style>
            </local:FieldEditor.Style>-->
        </local:FieldEditor>
    </DataTemplate>
  </ListView.ItemTemplate>
</ListView>

这是一个错误VirtualizingStackPanel吗？还有其他人遇到过类似的问题吗？任何解决方法？

更新：

在连接时将此错误报告给 MS - https://connect.microsoft.com/VisualStudio/feedback/details/734113/virtualizingstackpanel-not-handling-collapsed-items-correctly

4

2 回答 2

6

我设法重现了您的问题。它肯定看起来像VirtualizingStackPanel. 一种解决方法是将隐藏项的高度设置为零而不是折叠它们：

<DataTrigger Binding="{Binding Status}" Value="False">
    <Setter Property="Height" Value="0" />
    <Setter Property="IsEnabled" Value="False"/>
    <!--<Setter Property="Visibility" Value="Collapsed" />-->
</DataTrigger>
于 2012-02-10T21:37:01.430 回答
2

对于正在寻找一种方法来继续依赖可见性但也删除额外间距的其他人，我通过删除以下样式中的 Padding 来修复它ListBoxItem：

<ListBox.ItemContainerStyle>
    <Style TargetType="ListBoxItem">
        <Setter Property="Padding" Value="0"/>
    </Style>
</ListBox.ItemContainerStyle>

似乎ListBoxItem的默认 Padding 是 3。

于 2018-12-20T16:11:20.733 回答