ListBox SelectedItem binded: page navigation, getting item, showing its properties in a new view and reset SelectedIndex. How can i do?

Question

i'm trying to apply the MVVM pattern in my application with MVVM Light. I've a databinded ListBox...

MainView.xaml [extract]

<ListBox Name="recipesListBox" 
                             ItemsSource="{Binding RecipeList}"
                             SelectedItem="{Binding SelectedRecipe, Mode=TwoWay}"
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch"
                             Grid.Row="1"
                             Margin="12,0,12,0"
                             SelectionChanged="recipesListBox_SelectionChanged" >

MainViewModel.cs [extract]

    private Recipe selectedRecipe;

    public Recipe SelectedRecipe
    {
        get
        {
            return selectedRecipe;
        }
        set
        {
            selectedRecipe = value;
            RaisePropertyChanged("SelectedRecipe");
        }
    }

...that performs a page navigation on SelectionChanged:

MainView.xaml.cs [extract]

private void recipesListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            string destination = "/RecipeView.xaml";
            if (recipesListBox.SelectedIndex == -1) // If selected index is -1 (no selection) do nothing
                return;
            this.NavigationService.Navigate(new Uri(destination, UriKind.Relative));
            //recipesListBox.SelectedIndex = -1; // Reset selected index to -1 (no selection)
        }

After // you can see the old code that reset the index after page navigation - now, with binded data, obviously it also set null my selected item! How can i do for navigate to a new view, show the property of selected item and reset the selected index when i go back? Thank you!

Answer 1

The way I did it was this:

protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
    if (listBox.SelectedItem != null)
    {
        listBox.SelectedIndex = -1;
    }

    base.OnNavigatedFrom(e);
}

then add the following to SelectionChanged event

if(SelectedItem != null)
{
    // Do something with SelectedItem
}