如何让ListBoxItem显示序号
<ListBox ItemsSource="{Binding}" AlternationCount="{Binding Path=Count}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListBoxItem},
Path=(ItemsControl.AlternationIndex)}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>