mvvm ComboBox selection in Listview - wpf

Question

I am trying to display a collection of objects in a wpf-Listview and provide a combobox for selection of values from an other collection.
Some code to illustrate my problem:
XAML: (Window gets its DataContext set in app.xaml.cs)
<ListView ItemsSource="{Binding Path=Books}" SelectedItem="{Binding Path=CurrentBook}">
<ListView.View>
<GridView>
<GridViewColumn Header="author" DisplayMemberBinding="{Binding author}" />
<GridViewColumn Header="title" DisplayMemberBinding="{Binding title}" />
<GridViewColumn Header="genre">
<GridViewColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.Genres}" IsSynchronizedWithCurrentItem="true" DisplayMemberPath="genreName" SelectedItem="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.CurrentBook_Genre}">
<ComboBox.ItemTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding genreName}" />
<TextBlock Text="{Binding genreDescription}" />
</StackPanel>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
For now is "CurrentBook_Genre" a Property of the MainWindowViewModel, the according value of the Item shown in the ListView is set by its setter.
Like that the same ComboBox is shown in every "row" of the ListView.
I guess I need some kind of "EditValueTemplate" and "ShowValueTemplate" and a Selector of some kind, it would be fine, if the ComboBox gets shown only in the row which is in edit-mode - i guess this is a common thing for most DataDriven apps, so maybe there is a way more easy iam not aware of.
The only good explanation for this was
http://tech.pro/tutorial/857/wpf-tutorial-using-the-listview-part-3-in-place-edit
But they are working with dependency-properties, opposed to the ViewModel-wrapped models iam using.

Answer 1

There is a much easier way to get one control displayed when a grid row is edited and another when it is not edited than the example that you found. Try this instead:
<DataGrid ItemsSource="{Binding Books}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.CurrentBook_Genre.genreName}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.Genres}" IsSynchronizedWithCurrentItem="true" DisplayMemberPath="genreName" SelectedItem="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.CurrentBook_Genre}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
This will display a ComboBox when the row is being edited and a plain old TextBlock when it is not.