如何从ListPickerFlyout检索项目？

Question

I created a ListPickerFlyout and I would like, through a button, select an item from the list. In XAML I have done so:

<Button x:Name="BottoneFiltraCittaNotizie" Click="BottoneFiltraCittaNotizie_Click" Style="{StaticResource ButtonSearchStyle}" Grid.Row="0" BorderBrush="{x:Null}" Foreground="Gray" Margin="0,-12,0,0">
    <Button.Flyout>
       <ListPickerFlyout ItemsSource="{Binding Source={StaticResource Museum}}">
              <ListPickerFlyout.ItemTemplate>
                    <DataTemplate>
                          <StackPanel>
                              <TextBlock Text="{Binding NomeProvincia}" HorizontalAlignment="Left"/>
                          </StackPanel>
                    </DataTemplate>
              </ListPickerFlyout.ItemTemplate>
       </ListPickerFlyout>
    </Button.Flyout>
</Button>

in c # I want to recover the selected item, and then do some operations. MSDN there is SelectedItem instead I can not find it, and I said that does not exist, how could I do?

private void BottoneFiltraCittaNotizie_Click(object sender, RoutedEventArgs e)
        {
            Regioni region = ListPickerFlyout.SelectedItem as Regioni; //ERROR!!
            string regione = region.NomeRegione;
            var GruppiAllNEWS = NotizieFB.Where(x => x.TAG.Contains(regione)).OrderBy(x => x.Data).Reverse();

        }

Answer 1

Add a property of your object to your view model (or code behind, or whatever you use as your datacontex), and then add a binding to that on that list.

Assuming you have public MyObject my_object {get;set;} in your datacontext, you should have on your xaml something like:

<ListPickerFlayout ...
                   SelectedItem = {binding my_object;} />

This way it knows that whatever is selected, will be that object in the data context, and you can access it from your code, by simply using the above property:

public class SomeClass {
    // this is your code behind file
    public MyObject my_object {get;set;} 

    // this is where you go when you hit the button
    OnButtonClick(sender, event) {
        //my_object is accessible here. Assuming it has a DoSomething method, you can:
        my_object.DoSomething();
    }
}

Alternatively, as this msdn suggests, you won't have to bind to a property (i would, since i'll try to do it in a MVVM way), and all you'll have to do is cast the sender and use it's selected item, something along:

void PrintText(object sender, SelectionChangedEventArgs args)
{
    // get your object with the cast, and then get it's item
    ListBoxItem lbi = ((sender as ListBox).SelectedItem as ListBoxItem);
    // then you can use it like:
    tb.Text = "   You selected " + lbi.Content.ToString() + ".";
}