WP7 Tombstoning - cannot set list selected item value from State data

Question

I am setting up tombstoning for a simple WP7 app. I have a list of items, and I want to save the ListBox.SelectedIndex in State memory, and on returning to the page, have that item selected in the list.

When I try the following code, saving the value seems to work (I have confirmed by displaying it in a MessageBox) but the list item is not selected.

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {

            if (State.ContainsKey("activeResult"))
            {
                listBox1.SelectedIndex = Convert.ToInt32(State["activeResult"]);
            }
            base.OnNavigatedTo(e);
        }

        protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
        {
            State["activeResult"] = listBox1.SelectedIndex;
            base.OnNavigatedFrom(e);
        }

The code compiles with no errors - but the listbox item is just never selected. thanks for your help! cheers Will

Answer 1

Wild guess says you're databinding the List after you set the SelectedIndex, and as such it have no effect (unless it's zero).

Solution: Ensure your ViewModel is initialized, and loaded before you set the SelectedIndex, or databind the SelectedIndex property, and set it on your ViewModel, rather than on the UI component.