C＃WPF和Sqlite：當嘗試從sqlite數據庫表中讀取數據時，Datagrid顯示最后一個表記錄

Question

我無法弄清楚為什么我的數據網格會顯示Sqlite數據庫中的最后一個表記錄。 這是我寫的代碼。

    ObservableCollection<Activity> _activitiesList = new ObservableCollection<Activity>();



  while (reader.Read())
{
   _act.Name = reader.GetString(reader.GetOrdinal("Activity"));
   _act.Customer = reader.GetString(reader.GetOrdinal("ActivityCustomer"));
   _act.Activitytpe = reader.GetString(reader.GetOrdinal("ActivityNature"));
   string st = reader.GetString(reader.GetOrdinal("StartedAt"));
   _act.StartedAt = Convert.ToDateTime(st);
   string et = reader.GetString(reader.GetOrdinal("FinishedAt"));
   _act.EndedAt = Convert.ToDateTime(et);
   //string _ratio = reader.GetString(reader.GetOrdinal("ActivityRatio"));
   //_act.ActivityRatio = Convert.ToDouble(_ratio);
   _act.Notes = reader.GetString(reader.GetOrdinal("Notes"));
   string _hldy = reader.GetString(reader.GetOrdinal("Holiday"));
   _act.IsHoliday = Convert.ToBoolean(_hldy);
   _activitiesList.Add(_act);
}
ActivitiesDataGrid.ItemsSource=_activitiesList;

Answer 1

在里面，您必須實例化一個新的活動類：

while (reader.Read())
{ 
      Activity _act=new Activity();
      ....
}

Answer 2

您可以在while循環內部為“ Activity”類創建新的對象實例嗎？

 ObservableCollection<Activity> _activitiesList = new ObservableCollection<Activity>();

**while (reader.Read())
            {
                ***_act = new Activity();***
                _act.Name = reader.GetString(reader.GetOrdinal("Activity"));
               ....
               ....
             }**