&tag(WPF,TreeView);
<TreeView>
<TreeView.ItemContainerStyle>
<Style TargetType="TreeViewItem">
<Setter Property="IsExpanded" Value="True"/>
</Style>
</TreeView>
<TreeView ItemsSource={Binding Persons}>
<TreeView.ItemContainerStyle>
<Style TargetType="TreeViewItem">
<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
</Style>
</TreeView>