title: DateTime need convert to string wpf
body: <pre><code>&lt;DataGrid....
  &lt;DataGrid.Resources&gt;
    &lt;DataTemplate DataType="{x:Type DateTime}"&gt;
          &lt;TextBlock Text="{Binding StringFormat={}{0:d}}"  /&gt;
    &lt;/DataTemplate&gt;
  &lt;/DataGrid.Resources&gt;
  ...
   &lt;DataGridTemplateColumn Header="Время оплаты"&gt;
      &lt;DataGridTemplateColumn.CellTemplate&gt;
            &lt;DataTemplate&gt;
                  &lt;TextBlock VerticalAlignment="Center" Text="{Binding date_payment}"  Width="Auto" Height="Auto" /&gt;
             &lt;/DataTemplate&gt;
       &lt;/DataGridTemplateColumn.CellTemplate&gt;
   &lt;/DataGridTemplateColumn&gt;
  </code></pre>
  
  <p>but this column have type <code>DateTime</code>...
  i need convert this column on this type(string), because i need rename value row on this column, i use event <code>LoadingRow</code> so</p>
  
  <pre><code>DataRowView item = e.Row.Item as DataRowView;
  DataRow row = item.Row;
  var time = row[4];
  if (Convert.ToString(time) == "01.01.0001 0:00:00")
  {
     row[4] = "No payment";
  }
  </code></pre>
  
  <p>but its wrong, row no converting to string, please help</p>