信息没有出现

我已经创建了数据库和所有的编码。但是信息现在出现在电话里。我怎样才能让它们出现?它无法向我展示任何细节。它告诉我，它不能从编码"this. listbox"转到这一行。ItemsSource = CarScores;"

//Main Page Coding .xaml.CS
 namespace carDatabaseCreater
{
 public partial class MainPage : PhoneApplicationPage
 {
    public static List<Car> CarScoresList = new List<Car>();
    Uri uri;
    Grid CarGrid;
    CarHisrotyRepository CarHisrotyRepository;
    ObservableCollection<Car> CarScores;

    // Constructor
    public MainPage()
    {
        InitializeComponent();

        this.DisplayCarHistory();
        this.UpdateCarScoresFromDB();
    }

      public void SaveCarToCarHistory(Car _Car)
      {
           CarHisrotyRepository _CarHisrotyRepository = new CarHisrotyRepository();
         Car item0 = new Car() { CarName = "Arion", CarSupplierName = "Bahowan", CarImage = "Image/BMW.jpg", CarCompanyName = "Toyota" };
         Car item1 = new Car() { CarName = "Arion", CarSupplierName = "Bahowan", CarImage = "Image/BMW.jpg", CarCompanyName = "Toyota" };
         Car item2 = new Car() { CarName = "Arion", CarSupplierName = "Bahowan", CarImage = "Image/BMW.jpg", CarCompanyName = "Toyota" };
         Car item3 = new Car() { CarName = "Arion", CarSupplierName = "Bahowan", CarImage = "Image/BMW.jpg", CarCompanyName = "Toyota" };
         Car item4 = new Car() { CarName = "Arion", CarSupplierName = "Bahowan", CarImage = "Image/BMW.jpg", CarCompanyName = "Toyota" };
         CarScoresList.Add(item0);
         _CarHisrotyRepository.Save(item0);
        CarScoresList.Add(item1);
         _CarHisrotyRepository.Save(item1);
         CarScoresList.Add(item2);
         _CarHisrotyRepository.Save(item2);
         CarScoresList.Add(item3);
         _CarHisrotyRepository.Save(item3);
         CarScoresList.Add(item4);
         _CarHisrotyRepository.Save(item4);

     }
     private void UpdateCarScoresFromDB()
     {
         CarHisrotyRepository CarHisrotyRepository = new carDatabaseCreater.CarHisrotyRepository();
         List<Car> AllGames = CarHisrotyRepository.allQuery(CarHisrotyRepository.CarContext).ToList();

         }

     public void DisplayCarHistory()
     {
         this.CarHisrotyRepository = new CarHisrotyRepository();
         // Get Game History from IsoStore
         List<Car> CarHistory = this.CarHisrotyRepository.Load();
         // Display to Screen
        CarScores = new ObservableCollection<Car>(CarHistory);
        this.listBox.ItemsSource = CarScores;// the Error appears here
      }
    }
   }