public void InitData(string dId)
 {
     if (!string.IsNullOrEmpty(dId))
     {
         var district = ShanghaiPostalContext.Instance.Districts.FirstOrDefault(d => d.Id == dId);
         if (null != district)
         {
             District = district;
         }
     }
 }
 public DistrictDetailViewModel()
 {
     if (IsInDesignMode)
     {
         District = new District()
         {
             Id = "1",
             Name = "黄浦区",
             PostalCodes = ShanghaiPostalContext.Instance.PostalCodes.OrderBy(c => c.Code).Take(10).ToObservableCollection()
         };
     }
 }