private void Button_Click(object sender, RoutedEventArgs e)        {            Popup1.PlacementTarget = TesTextBox;            Popup1.Placement = PlacementMode.Bottom;            Popup1.IsOpen = true;        }        private void TestDataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)        {            TesTextBox.Text = (dataGrid.SelectedItem as DataRowView).Row["c_AirStrategyExpCode"].ToString();        }

dataGrid.ItemsSource = ds.Tables[0].DefaultView;            dataGrid.LoadingRow += DataGridOnLoadingRow;