防止在WPF DataGrid中选择多行

我在WPF数据网格中有以下XAML标记：

<DataGrid ItemsSource="{Binding ResultList}" Grid.ColumnSpan="4" Grid.Row="7" Height="150" 
          HorizontalAlignment="Left" Margin="10,0,0,0" Name="gvResults" 
          VerticalAlignment="Bottom" Width="590" AutoGenerateColumns="False" SelectionChanged="gvResults_SelectionChanged"
           SelectionUnit="FullRow">
    <DataGrid.Columns>
        <DataGridTextColumn IsReadOnly="True" Binding="{Binding Name}" Header="Name" ScrollViewer.VerticalScrollBarVisibility="Auto" Width="190" />
        <DataGridTextColumn IsReadOnly="True" Binding="{Binding Surname}" Header="Surname" Width="190" />
        <DataGridTextColumn IsReadOnly="True" Binding="{Binding Age}" Header="Age" Width="*" />
    </DataGrid.Columns>
</DataGrid>

是否可以防止用户在按住Ctrl键或用鼠标选择多行时选择多行？

我在SelectionChanged事件中尝试了以下代码，但它不起作用：

private void gvResults_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (gvResults.SelectedItems.Count > 1)
    {
        e.Handled = true;
    }
}