DataBound 动态数据绑定

需要有人告诉GridView 数据更新了 >.<

 //private List<Contact> Contacts;
 private ObservableCollection<Contact> Contacts;

ItemsSource="{x:Bind Contacts}  //ちょっと　UPDATE


   //Contacts = new List<Contact>();
            Contacts = new ObservableCollection<Contact>();