DataTemplate内部的DataTemplate-ListBox内部的ListBox

<RoomName>
    <Kid Name>
    <Kid Name>
<RoomName>
    <Kid Name>
<RoomName>
    <Kid Name>
    <Kid Name>
    <Kid Name>

class Room
{
  ObservableCollection<kid> Kids = new Ob...
}

class School
{
  ObservableCollection<Room> Rooms = new Ob...
}

class kid
{
  Name;
  Size;
  (...)
}

School BigSchool = new School();
MainListBox.DataContext = BigSchool;

<Window
        xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\"
        xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\"
        xmlns:local=\"clr-namespace:Rapideo_Client\" mc:Ignorable=\"d\"
        x:Class=\"Rapideo_Client.MainWindow\"
        Title=\"Client\" SnapsToDevicePixels=\"True\" Height=\"400\" Width=\"625\">
    <Window.Resources>
        <DataTemplate x:Key=\"kidTemplate\" DataType=\"Kid\">
            <StackPanel Orientation=\"Vertical\">
                <TextBlock Text=\"{Binding Path=Name}\" FontWeight=\"Bold\"></TextBlock>
                <Label Content=\"{Binding Path=Size}\"/>
            </StackPanel>
        </DataTemplate>
        <DataTemplate x:Key=\"roomTemplate\" DataType=\"Room\">
            <StackPanel Orientation=\"Vertical\">
                <Label Content=\"{Binding Path=Kids.Count}\"/>
                <ListBox ScrollViewer.HorizontalScrollBarVisibility=\"Disabled\" ScrollViewer.VerticalScrollBarVisibility=\"Disabled\" ItemsSource=\"{Binding Path=Kids}\" ItemTemplate=\"{DynamicResource kidTemplate}\" />
            </StackPanel>
        </DataTemplate>
    </Window.Resources>

    <ListBox ScrollViewer.HorizontalScrollBarVisibility=\"Disabled\" ScrollViewer.VerticalScrollBarVisibility=\"Visible\" x:Name=\"MainListBox\" Grid.Column=\"1\" ItemsSource=\"{Binding Rooms}\" ItemTemplate=\"{DynamicResource roomTemplate}\" />

</Window>