/// <summary>
		/// Populates the page with content passed during navigation. Any saved state is also
		/// provided when recreating a page from a prior session.
		/// </summary>
		/// <param name="sender">
		/// The source of the event; typically <see cref="NavigationHelper"/>.
		/// </param>
		/// <param name="e">Event data that provides both the navigation parameter passed to
		/// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested and
		/// a dictionary of state preserved by this page during an earlier
		/// session.  The state will be null the first time a page is visited.</param>
		private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
		{
			Windows.Phone.UI.Input.HardwareButtons.BackPressed += HardwareButtons_BackPressed;
			// TODO: Create an appropriate data model for your problem domain to replace the sample data.
			try
			{
				item = e.NavigationParameter as BusItem;

				if (item == null)
				{
					item = new BusItem();
				}

				this.DefaultViewModel["Bus"] = item;

				if (string.IsNullOrEmpty(item.OperationsTime))
				{
					thoigianhoatdong_text.Text = "Chưa có dữ liệu";
				}
				if (string.IsNullOrEmpty(item.Frequency))
				{
					giancach_text.Text = "Chưa có dữ liệu";
				}
				if (string.IsNullOrEmpty(item.Cost))
				{
					giave_text.Text = "Chưa có dữ liệu";
				}
				if (string.IsNullOrEmpty(item.RouteGo))
				{
					luotdi_text.Text = "Chưa có dữ liệu";
				}
				if (string.IsNullOrEmpty(item.RouteReturn))
				{
					luotve_text.Text = "Chưa có dữ liệu";
				}
			}
			catch (Exception exc)
			{
				string errMsg = exc.Message;
			}
		}
        /// <summary>
        /// Populates the page with content passed during navigation. Any saved state is also
        /// provided when recreating a page from a prior session.
        /// </summary>
        /// <param name="sender">
        /// The source of the event; typically <see cref="NavigationHelper"/>.
        /// </param>
        /// <param name="e">Event data that provides both the navigation parameter passed to
        /// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested and
        /// a dictionary of state preserved by this page during an earlier
        /// session. The state will be null the first time a page is visited.</param>
        private async void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
        {
			datagroup = await SampleDataSource.GetItemsAsync();
			loadJSONprogressbar.Opacity = 0;
			this.DefaultViewModel[FirstGroupName] = datagroup;
        }
		/// <summary>
		/// Populates the page with content passed during navigation.  Any saved state is also
		/// provided when recreating a page from a prior session.
		/// </summary>
		/// <param name="sender">
		/// The source of the event; typically <see cref="NavigationHelper"/>
		/// </param>
		/// <param name="e">Event data that provides both the navigation parameter passed to
		/// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested and
		/// a dictionary of state preserved by this page during an earlier
		/// session.  The state will be null the first time a page is visited.</param>
		private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
		{
			
		}