C# WPF DataTrigger从不激发以扩展TreeView

我有下面的XAML，当特定属性ExpandNodes为True时，它应该扩展我的整个树视图，但它从未被触发

<TreeView>
    <TreeView.ItemContainerStyle>
            <Style TargetType="{x:Type TreeViewItem}">

                <Setter Property="IsExpanded" Value="False" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding ExpandNodes}" Value="True">
                        <Setter Property="IsExpanded" Value="True" />
                    </DataTrigger>
                    <DataTrigger Binding="{Binding ExpandNodes}" Value="False">
                        <Setter Property="IsExpanded" Value="False" />
                    </DataTrigger>
                </Style.Triggers>

            </Style>
        </TreeView.ItemContainerStyle>

// some other code

</TreeView>

---

太复杂了，您可以简单地将IsExpanded属性绑定到对象并引发PropertyChanged事件

<TreeView>
    <TreeView.ItemContainerStyle>
         <Style TargetType="{x:Type TreeViewItem}">
           <Setter Property="IsExpanded" Value="{Binding ExpandNodes, 
            Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, 
            TargetNullValue=False}" />
         </Style>
     </TreeView.ItemContainerStyle>
// some other code
</TreeView>

---

当ExpandNodes值更改时，会有一个属性更改通知？是的，请参阅上面我对ViewModel的部分编辑。如果有一个ExpandNodes属性与ItemsSource集合处于同一级别，请尝试执行此操作的{Binding DataContext.ExpandNodes，RelativeSource={RelativeSource AncestorType=TreeView}。非常感谢。

<TreeView>
    <TreeView.ItemContainerStyle>
         <Style TargetType="{x:Type TreeViewItem}">
           <Setter Property="IsExpanded" Value="{Binding ExpandNodes, 
            Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, 
            TargetNullValue=False}" />
         </Style>
     </TreeView.ItemContainerStyle>
// some other code
</TreeView>