private void BuildAppBar()
{
_appBarButtons = new List<ApplicationBarIconButton>();
_appBarButtons.Add(new ApplicationBarIconButton());
_appBarButtons[0].IconUri = new Uri("\\Assets\\Icons\\send.png", UriKind.Relative);
_appBarButtons[0].Text = "send";
_appBarButtons[0].IsEnabled = false;
_appBarButtons[0].Click += Send_Click;
_appBarButtons.Add(new ApplicationBarIconButton());
_appBarButtons[1].IconUri = new Uri("\\Assets\\Icons\\cancel.png", UriKind.Relative);
_appBarButtons[1].Text = "cancel";
_appBarButtons[1].IsEnabled = true;
_appBarButtons[1].Click += Cancel_Click;
ApplicationBar.Buttons.Clear();
foreach (var button in _appBarButtons)
ApplicationBar.Buttons.Add(button as IApplicationBarIconButton);
}