Question

does anyone know of a bug in listpicker that prevents it from changing selected items when expansion mode is set to full mode only. It always for some reason goes back to the default item that is selected.

Answer 1

I am assuming that you have some code in your Page_Loaded which populates and/or sets the SelectedIndex of the ListPicker.

You need to ensure that you only set the value on entering the page.

    private void PhoneApplicationPage_Loaded(object sender, EventArgs e)
    {


        DataContext = App.ViewModel.something;
        if (MyListPicker.SelectedIndex == -1)
        {
            MyListPicker.ItemsSource   = App.ViewModel.SomeList;
            MyListPicker.SelectedIndex = App.ViewModel.MyBinding;
        }
    }

You may also ensure that you ignore the startup selection changes (which can fire several times when loading and binding in a page) and only catch user initiated changes.

    private void MyListPicker_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (e.RemovedItems != null && e.RemovedItems.Count > 0)
        {
            if (this.MyListPicker.SelectedItem != null)
            {              
                // Do something
            }
        }  
    }