wpf DataGrid加载行号

<DataGrid Name="tkdg" HorizontalContentAlignment="Center" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False" 
LoadingRow="tkdg_LoadingRow">
                           。。。。。

  private void tkdg_LoadingRow(object sender, DataGridRowEventArgs e)
        {
            //加载行
            e.Row.Header = e.Row.GetIndex() + 1;
        }