windows phone不同页面间传值

在windows phone中，不同页面间传值是用以下代码就可以了

PhoneApplicationService.Current.State[“strKey”]

我自己封装的代码：

TripDealer.cs:

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Shell;

namespace lifeCircle.Classes
{
    public class TripDealer
    {
        private const string tripKey = "trip";

        public TripInfo CurrentTrip
        {
            get
            {
                if (!PhoneApplicationService.Current.State.ContainsKey(tripKey))
                {
                    return null;
                }
                else
                {
                    return PhoneApplicationService.Current.State[tripKey] as TripInfo;
                }
            }
            set { PhoneApplicationService.Current.State[tripKey] = value; }
        }
       
    }
}

consuming Code:

using lifeCircle.Classes;

TripDealer objDealer = new TripDealer();

if (null == objDealer.CurrentTrip)
            {
                tbDate.Text = DateTime.Now.ToString("yyyy-MM-dd");
            }

if (null == objDealer.CurrentTrip)
            {
                objDealer.CurrentTrip = new TripInfo();
            }
            objDealer.CurrentTrip.Name = tbTripName.Text;
            objDealer.CurrentTrip.TripDate = DateTime.Parse(tbDate.Text);
            objDealer.CurrentTrip.MemberList = tbMembers.Text;
            NavigationService.Navigate(new Uri("/Pages/TripEditSecond.xaml",UriKind.Relative));