private void OnChannelUriChanged(Uri value)
{
   Dispatcher.BeginInvoke(() =>
   {
      txtURI.Text = value.ToString();
   });

   Debug.WriteLine("URI: " + value.ToString());
}

Step 5: Create button event handler of btnCreateChannel which will invoke

private void btnCreateChannel_Click(object sender, RoutedEventArgs e)
{
   SetupChannel();
}

Step 6: Place SetUpChannel method code in the MainPage.xaml.cs. If the channel is already exist but ChannelURI is null we need to close the channel and reopen it. If channel does not exist create HttpNotificationChannel and attach NotificationChannelUriEventArgs and NotificationEventArgs event handler. 

private void SetupChannel()
{
   HttpNotificationChannel httpChannel = null;
   string channelName = "DemoChannel";

   //if channel exists, retrieve existing channel
   httpChannel = HttpNotificationChannel.Find(channelName);

   if (httpChannel != null)
   {
      //If we cannot get Channel URI, then close the channel and reopen it
      if (httpChannel.ChannelUri == null)
      {
         httpChannel.UnbindToShellToast();
         httpChannel.Close();
         SetupChannel();
         return;
      }
      else
      {
         OnChannelUriChanged(httpChannel.ChannelUri);
      }
      BindToShell(httpChannel);
   }
   else
   {
      httpChannel = new HttpNotificationChannel(channelName);
      httpChannel.ChannelUriUpdated += new EventHandler<NotificationChannelUriEventArgs>(httpChannel_ChannelUriUpdated);
      httpChannel.ShellToastNotificationReceived += new EventHandler<NotificationEventArgs>(httpChannel_ShellToastNotificationReceived);
      httpChannel.Open();
      BindToShell(httpChannel);
   }
}

Step 7: If the application is running the below method will read the notification message and print on the textbox.

void httpChannel_ShellToastNotificationReceived(object sender, NotificationEventArgs e)
{
   Dispatcher.BeginInvoke(() =>
   {
      txtURI.Text = "Toast Notification Message Received: ";
      if (e.Collection != null)
      {
         Dictionary<string, string> collection = (Dictionary<string, string>)e.Collection;
         System.Text.StringBuilder messageBuilder = new System.Text.StringBuilder();
         foreach (string elementName in collection.Keys)
         {
            txtURI.Text += string.Format("Key: {0}, Value:{1}\r\n", elementName, collection[elementName]);
         }
      }
   });
}

Step 8: BindToShellToast of HttpNotificationChannel needs to be called to bind toast notification.

private static void BindToShell(HttpNotificationChannel httpChannel)
{
   try
   {
      httpChannel.BindToShellTile();
   }
   catch (Exception)
   {
   }
}

Step 9: Below code will be triggered whenever ChannelURI will be updated.

void httpChannel_ChannelUriUpdated(object sender, NotificationChannelUriEventArgs e)
{
   //You get the new Uri (or maybe it's updated)
   OnChannelUriChanged(e.ChannelUri);
}

Step 10: Create a Maroon image of 173 X 173 and add the image in the project. Change the Build Action property of the image to Content from Resource.

On running the application Windows Phone 7 emulator will look like below image.