Windows Phone 7: How to notify data is updated in ListBox?

Question

I have above scenario: If user click on ListBox, it will either have sub items (again ListBox) or detail view.

So what i did currently is: Whenever user clicks any item, made a web call and filled up the same ListBox if clicked item is having further sub items.

Now, issue comes in picture:

1. Suppose i am in 4th screen (detail view),
2. Moved to the 3rd and 2nd screen with data maintained as stack (Its working fine, yes i am maintaining data in ObservableCollection<ObservableCollection<MyObjects>> so while moving back, i am fetching data from there)
3. Now, if i click any item in screen 2, it will open detail view for the screen 3 ListBox data.

Means that ListBox is not getting notified that we have filled data inside OnBackKeyPress()

FYI, i am filling up ListBox and WebBrowser in the same page., so my problem is that how do i notify ListBox once i filled up data from stack which i have maintained?

Yes i have also implemented INotifyPropertyChanged but don't know why its not working.

Please check my code:

1. ListBox and WebView screen: http://pastebin.com/K1G27Yji
2. RootPageItem class file with the implementation of INotifyPropertyChanged: http://pastebin.com/E0uqLtVG

sorry for pasting code in above way, i did as question is being long.

Problem:

How do i notify ListBox that data is changed from OnBackKeyPress?

Answer 1

Oops it was a silly mistake i made.

I forgot to set items[] array inside OnBackKeyPress() but was accessing while clicking item, hence its having items[] data of last step we moved in forward direction, it was executing the same data.

Now, i have just included a single line and it has solved my problem.

 items = listRootPageItems.ToArray();  // resolution point

So final code of onBackKeyPress() is:

/**
 * While moving back, taking data from stack and displayed inside the same ListBox
 * */
 protected override void OnBackKeyPress(CancelEventArgs e)
 {
     listBox1.Visibility = Visibility.Visible;
     webBrowser1.Visibility = Visibility.Collapsed;
     listBox1.SelectedIndex = -1;

     if (dataStack.Count != 0)
     {
          listBox1.ItemsSource = null;
          listRootPageItems = dataStack[dataStack.Count-1];
          listBox1.ItemsSource = listRootPageItems;

               items = listRootPageItems.ToArray();  // resolution point
          dataStack.Remove(listRootPageItems);

          e.Cancel = true;
      }
 }