It should be a two stepped procedure -
a) Set the IsReadOnly property to true in the XAML
<ns:DataGrid x:Name="datagrid1" ItemsSource="{Binding Data}" IsReadOnly="True">
</ns:DataGrid>
b) Add a "selectionchanged" event handler.
<ns:DataGrid x:Name="datagrid1" ItemsSource="{Binding Data}" IsReadOnly="True" SelectionChanged="datagrid1_SelectionChanged">
</ns:DataGrid>
c) In the SelectionChanged event, choose to remove the selected item. Please see below.
private void datagrid1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
datagrid1.SelectedItem = null;
}
Hope this helps.