/DataBoundApp1/DetailsPage.xaml.cs

using System;

using System.Linq;

using System.Windows;

using System.Windows.Navigation;

using DataBoundApp1.ViewModels;

using Microsoft.Phone.Controls;



namespace DataBoundApp1

{

	public partial class DetailsPage : PhoneApplicationPage

	{

		// Constructor

		public DetailsPage()

		{

			InitializeComponent();

		}



		// When page is navigated to set data context to selected item in list

		protected override void OnNavigatedTo(NavigationEventArgs e)

		{

			string selectedIndex = "";

			if (NavigationContext.QueryString.TryGetValue("selectedItem", out selectedIndex))

			{				

				DataContext = App.ViewModel.Sessions.SingleOrDefault(s => s.Uri == selectedIndex);

			}

		}



		private SessionViewModel Session

		{

			get { return (SessionViewModel) this.DataContext; }

		}



		private void ToggleFavorite(object sender, EventArgs e)

		{

			if (App.ViewModel.Favorites.Any(s => s.Start == Session.Start))

			{

				MessageBox.Show("You've alread added the session for this slot. Don't do that.");

				return;

			}



			var foundSession = App.ViewModel.Favorites.SingleOrDefault(s => s.Uri == Session.Uri);



			if (foundSession != null)

			{

				App.ViewModel.Favorites.Remove(foundSession);

				MessageBox.Show("session removed.");

			}

			else

			{

				App.ViewModel.Favorites.Add(Session);

				MessageBox.Show("session added.");

			}





		}

	}

}