[Q] ListBox Binding Error with Observable Collection

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Hi all!

Since days I have a problem now. I have an app that manage Entries in a list A. If one of these entries End-Date is today I whant that entry to be shown in a second list B. This is checked when I return from the "addNewItem" Window so I use onNavigatedTo.

// Static Variables
        public static ObservableCollection<Item> lstToday = new ObservableCollection<Item>();
        public static ObservableCollection<Item> lstWeek = new ObservableCollection<Item>();
        public static ObservableCollection<Item> lstAll = new ObservableCollection<Item>();

        // Constructor
        public MainPage()
        {
            InitializeComponent();
            MessageBox.Show("Initialize Component");
            lbToday.ItemsSource = lstToday;
            lbWeek.ItemsSource = lstWeek;
            lbAll.ItemsSource = lstAll;
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            DateTime currentDate = DateTime.Now;
            foreach (Item item in lstAll)
            {
                if (item.endDate.ToString("yyyy'-'MM'-'dd").Equals(currentDate.ToString("yyyy'-'MM'-'dd")))
                { 
                    lstToday.Add(item);
                    MessageBox.Show("Item '" + item.name + "' added to Todaylist");
                }
            }
        }

        private void appBarNew_Click(object sender, EventArgs e)
        {
            NavigationService.Navigate(new Uri(string.Format("/EditAddItem.xaml"), UriKind.Relative));
        }

After that I get an "System.Diagnostics.Debugger.Break();" error that doesn't occur when I delete "lbToday.ItemsSource = lstToday;" to avoid the ListBox Binding.

With lbAll ist runs without any problems!
Can I bind the Listbox direct to the ObservableCollection in XAML=
I really don't know, whats to do. So do you?

It would make my day!
Thanks!

What is the exception message and stack trace when the exception is thrown? (you can browse the properties of the exception using visual studio).

Your code actually works for me (although I had to make some assumptions about what is in lstAll as you don't mention that, and you may have an error in the DataTemplate for the listbox for binding your Item class)

Things to try:

Have you tried it with non static observable collections?

Use binding assignments in the xaml rather than setting the itemssource directly (e.g. using a viewmodel). Then you can let the phone engine worry about when to do the assigments. If you do that don't forget to set the page's datacontext property.

Try it with simple collections of strings first (rather than binding an 'item' class) so you can check it's working without a datatemplate.

Hope you fix it.

Ian