Group DataGrid with XmlDataProvider source - wpf

Question

I have a XmlDataProvider, a ListBox and a DataGrid.
The underlying xml file has this kind of structure:
<Root>
<Person name="test">
<item name="bla" value="test"/>
<item name="bla" value="test2"/>
</Person>
<Root>
The ListBox lists all persons, while the DataGrid lists all items, corresponding to the selected Person. This works as intended.
Now i want to group the data in the DataGrid, but having looked at examples i still don't get how to do it with an XmlDataProvider (how/where to create a ListCollectionView off of the XmlDataProvider).
Could someone please give me a quick xaml example for doing this by e.g grouping the items by name?:)
Thanks for any help in advance :)
regards
UPDATE:
Now the grouping works, but when i add something to the xml, it is not shown instantly anymore (in listbox or datagrid).What is wrong? I am really new to wpf, so there might be things redundant or unnecessary, i got no problems with you pointing them out :)
Here is the relevant code that is used:
<Grid.DataContext>
<XmlDataProvider x:Name="XmlData" Source="entries.xml" XPath="Root/Person" />
</Grid.DataContext>
<ListBox Name="PersonListBox"
ItemsSource="{Binding}"
ItemTemplate="{StaticResource listBoxTemplate}"
IsSynchronizedWithCurrentItem="True"
Visibility="Visible" SelectionMode="Single" SelectedIndex="-1" DataContext="{Binding}">
</ListBox>
<DataGrid IsSynchronizedWithCurrentItem="True" Name="itemGrid"
DataContext="{Binding ElementName=PersonListBox, Path=SelectedItem}"
CanUserAddRows="true"
IsReadOnly="true"
AutoGenerateColumns="False">
<DataGrid.Resources>
<CollectionViewSource x:Key="items" Source="{Binding XPath=item}">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="#name"/>
</CollectionViewSource.GroupDescriptions>
</CollectionViewSource>
</DataGrid.Resources>
<DataGrid.ItemsSource>
<Binding Source="{StaticResource items}"/>
</DataGrid.ItemsSource>
<DataGrid.Columns>
<DataGridTextColumn Width="*" Header="Name" Binding="{Binding XPath=#name}"/>
<DataGridTextColumn Header="Wert" Binding="{Binding XPath=#value}"/>
</DataGrid.Columns>
<DataGrid.GroupStyle>
<GroupStyle />
</DataGrid.GroupStyle>
</DataGrid>

Answer 1

Here is an example, should be quite self-explanatory but if something is not clear feel free to ask:
<DataGrid>
<DataGrid.Resources>
<CollectionViewSource x:Key="items" Source="{Binding SelectedItem, ElementName=lb}">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="#name"/>
</CollectionViewSource.GroupDescriptions>
</CollectionViewSource>
</DataGrid.Resources>
<DataGrid.ItemsSource>
<Binding Source="{StaticResource items}"/>
</DataGrid.ItemsSource>
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding XPath=#value}"/>
</DataGrid.Columns>
<DataGrid.GroupStyle>
<GroupStyle />
</DataGrid.GroupStyle>
</DataGrid>
(You can also set IsSynchronizedWithCurrentItem to true on the ListBox and then bind the Source via the current item instead (i.e. {Binding /, Source={StaticResource data}})