WP7 - accessing selected item in listbox when listbox is within an itemtemplate

Question

I have a Pivot item template that includes a listbox

 <controls:Pivot x:Name="MainPivot" ItemsSource="{Binding PivotItemHeaders}" Title="CLASS TIMETABLE"  >
        <controls:Pivot.HeaderTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding Description}"/>
            </DataTemplate>
        </controls:Pivot.HeaderTemplate>
        <controls:Pivot.ItemTemplate>
            <DataTemplate>
                <ListBox x:Name="Events" ItemsSource="{Binding allEventItems}" ItemTemplate="{StaticResource EventDisplay2}"/>
            </DataTemplate>
        </controls:Pivot.ItemTemplate>
    </controls:Pivot>

In the code behind I want to access the selectedItem of that listbox but I cannot 'get' to the listbox as such because ity is (presumably) within the template

i.e

this.NavigationService.Navigate(new Uri("/View/EventEdit.xaml?selectedEvent=" +  Events.SelectedItem, UriKind.Relative));

The Events listbox is not being recognised.

Assuminh I can pass get the object and pass it through as a parameter, what code can I use to retrieve it

I know its starts with protected override void OnNavigatedTo(NavigationEventArgs e) { if (NavigationContext.QueryString.ContainsKey("SelectedEvent")) {

But I am unsure of the syntax/code to extract out the object from the parameters

Appreciate how I can get the selectedItem from this listbox and the code to get the object being passed through

• thanks

Answer 1

Rather than attempt to access the ListBox, you could use the SelectionChanged event to be told when the value changes:

<ListBox x:Name="Events" 
         ItemsSource="{Binding allEventItems}" 
         ItemTemplate="{StaticResource EventDisplay2}"
         SelectionChanged="Event_SelectionChanged" />

And then in your code behind:

private void Event_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    this.selectedEvent = (EventItem)e.AddedItems[0];
}

You can access the value using NavigationContext.QueryString["selectedEvent"], but you can only store strings in navigation query strings. If your listbox is currently bound to objects, you'll need to select a key and then find that event from the second page using that key.