Trouble binding selected item in nested Listview - wpf

Question

I currently use a listview nested inside a listview as a way to show a Knockout style tournament graphically, backed up in ViewModel by SectionTreeOne, which contains a List of Lists of objects "TournamentNode". I cannot however get my selected "Tournament Node" to bind when I click on it.
<Grid Grid.Row="2">
<ListView ItemsSource="{Binding SectionTreeOne}">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate >
<DataTemplate>
<ListView ItemsSource="{Binding}" SelectionMode="Single"
SelectedItem="{Binding SelectedTournamentNode}">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
C# binding:
Collection
public List<List<TournamentNodeModel>> SectionTreeOne
{
get { return _sectionTreeOne; }
set
{
_sectionTreeOne = value;
base.OnPropertyChanged("SectionTreeOne");
}
}
Selected Item:
public TournamentNodeModel SelectedTournamentNode
{
get { return _selectedTournamentNode; }
set
{
if (value == _selectedTournamentNode)
return;
_selectedTournamentNode = value;
base.OnPropertyChanged("SelectedTournamentNode");
}
}

Answer 1

Try with the folowing binding:
SelectedItem="{Binding SelectedTournamentNode, Mode=TwoWay}"
Keep in mind that WinRT always use the OneWay binding mode as default unlike in WPF where it automatically selects a binding mode depending on the property nature or accessibility.
A good principle I used with WinRT to avoid this kind of mistake is to always explicitely specify the binding mode.
So I finally figured out what were the mistakes in your binding. Firstly, the SelectedItem binding mode has to be set to TwoWay explicitely as I stated above.
Secondly, the nested list was binding to an inner list in the SectionTreeOne list, therefore if you want to bind SelectedItem to a property on your view model, you have to rebind this property to the DataContext of the parent list using named elements. You were actually trying to bind to a non-existant property on the inner list instead of binding to the view model where the property is located.
<ListView x:Name="listView" ItemsSource="{Binding SectionTreeOne}">
...
<ListView.ItemTemplate >
<DataTemplate>
<ListView ItemsSource="{Binding}" SelectionMode="Single"
SelectedItem="{Binding Path=DataContext.SelectedTournamentNode, ElementName=listView, Mode=TwoWay}">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Do read the Visual Studio debugger output, it has really useful information about binding errors that could occur in the binding chain, especially if you bind a list nested in another list, it will save you lot of headaches!