.net 可见性=已折叠但不在DockPanel中工作

我试图让下面的文本块折叠起来，但它不起作用：

<DockPanel Grid.Column="1" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" LastChildFill="False" >
<DockPanel.Resources>
    <Style x:Key="ReferenceValues" TargetType="{x:Type TextBlock}">
        <Style.Triggers>
            <Trigger Property="Text" Value="">
                <Setter Property="Visibility" Value="Collapsed" />
            </Trigger>
            <Trigger Property="Text" Value="{x:Null}">
                <Setter Property="Visibility" Value="Collapsed" />
            </Trigger>
        </Style.Triggers>
    </Style>
</DockPanel.Resources>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropFullName}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropTitle}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropUserName}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropYear}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropEmailAddress}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropStartingPage}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropEndingPage}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropStartingDate}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropEndingDate}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropLastUpdate}" Margin="2,2,2,2"  Visibility="Visible"/>
<TextBlock Style="{StaticResource ReferenceValues}" FontFamily="Segoe UI Light" FontSize="14" DockPanel.Dock="Top" Text="{Binding PropFileFormat}" Margin="2,2,2,2"  Visibility="Visible"/>
...
</DockPanel>

...

---

当值为

null

或

时，它们仅显示为空白。
DockPanel
是否自动不呈现未显示的控件？（只有3个
TextBlock
可以容纳72像素。）
每个
TextBlock
上可见性属性的显式设置将覆盖样式。删除
Visibility=“Visible”
属性，文本块将根据您的样式按预期呈现

如果希望默认可见性可见，请在样式中设置默认可见性：

<Style x:Key="ReferenceValues" TargetType="{x:Type TextBlock}">
    <Setter Property="Visibility" Value="Visible" />
    <Style.Triggers>
        <Trigger Property="Text" Value="">
            <Setter Property="Visibility" Value="Collapsed" />
        </Trigger>
        <Trigger Property="Text" Value="{x:Null}">
            <Setter Property="Visibility" Value="Collapsed" />
        </Trigger>
    </Style.Triggers>
</Style>

属性值由依赖项属性值优先级决定。请参阅msdn中的此链接-