Binding ObservableCollection of ObservableCollections to nested ListView in TabControl TabItems - wpf

Question

Rather than declaring a tab for each of the ObservableCollections explicitly as in the first TabControl below I need them to generate dynamically as in the second TabControl and have the ItemsSource of the nested ListView set to each of the nested ObservableCollections.
In other words: Why aren't the ItemSource bindings of the nested ListViews in the second TabControl working? Is there a way to set the index of the nested ObservableCollection to the index of the containing ObservableCollection?
Or: How do I make the second dynamic TabControl and nested ListViews look like the first static TabControl and nested ListViews?
using System.Collections.ObjectModel;
using System.Windows;
namespace GridViewColumns2
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
ViewModel viewModel = new ViewModel();
viewModel.ThingCollections = new ObservableCollection<ThingCollection>();
viewModel.ThingCollections.Add(new ThingCollection { Name = "One" });
viewModel.ThingCollections[0].Things = new ObservableCollection<Thing>();
viewModel.ThingCollections[0].Things.Add(new Thing { Name = "One.One" });
viewModel.ThingCollections[0].Things.Add(new Thing { Name = "One.Two" });
viewModel.ThingCollections[0].Things.Add(new Thing { Name = "One.Three" });
viewModel.ThingCollections.Add(new ThingCollection { Name = "Two" });
viewModel.ThingCollections[1].Things = new ObservableCollection<Thing>();
viewModel.ThingCollections[1].Things.Add(new Thing { Name = "Two.One " });
viewModel.ThingCollections[1].Things.Add(new Thing { Name = "Two.Two" });
viewModel.ThingCollections[1].Things.Add(new Thing { Name = "Two.Three" });
DataContext = viewModel;
}
}
public class ViewModel
{
public ObservableCollection<ThingCollection> ThingCollections { get; set; }
}
public class ThingCollection
{
public string Name { get; set; }
public ObservableCollection<Thing> Things { get; set; }
}
public class Thing
{
public string Name { get; set; }
}
}
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TabControl>
<TabItem>
<TabItem.Header>One</TabItem.Header>
<TabItem.Content>
<ListView ItemsSource="{Binding Path=ThingCollections[0].Things}">
<ListView.View>
<GridView>
<GridViewColumn Width="120" Header="Name" DisplayMemberBinding="{Binding Name}" />
</GridView>
</ListView.View>
</ListView>
</TabItem.Content>
</TabItem>
<TabItem>
<TabItem.Header>Two</TabItem.Header>
<TabItem.Content>
<ListView ItemsSource="{Binding Path=ThingCollections[1].Things}">
<ListView.View>
<GridView>
<GridViewColumn Width="120" Header="Name" DisplayMemberBinding="{Binding Name}" />
</GridView>
</ListView.View>
</ListView>
</TabItem.Content>
</TabItem>
</TabControl>
<TabControl Grid.Column="1" ItemsSource="{Binding Path=ThingCollections}">
<TabControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</TabControl.ItemTemplate>
<TabControl.ContentTemplate>
<DataTemplate>
<ListView ItemsSource="{Binding Path=ThingCollections[0].Things}">
<ListView.View>
<GridView>
<GridViewColumn Width="120" Header="Name" DisplayMemberBinding="{Binding Name}" />
</GridView>
</ListView.View>
</ListView>
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
</Grid>

Answer 1

When you're in a DataTemplate, the DataContext is already that of the item (in your case, a ThingCollection class.
So instead of:
<ListView ItemsSource="{Binding Path=ThingCollections[0].Things}">
Use:
<ListView ItemsSource="{Binding Path=Things}">
To diagnose future binding errors, hit F5 (start debugging) and then take a look in the Output Window. All binding errors will be recorded there. In this case, it would've indicated that it cannot find a property named ThingCollections in the object ThingCollection.

Answer 2

Remove ThingCollections[0]. in BindingPath. The DataContext will be set for you to the right ThingCollection.
<ListView ItemsSource="{Binding Path=Things}">