How to hide a control if the underlying DataContext is null?

Question

I have an object in my view model that has a bunch of properties, some of them will occasionally be null. I don't want to just show some controls if these particular controls are null. How would I go about hiding the control if the bind is null? I was thinking of some sort of converter, but don't know how I'd go about doing it exactly. Any ideas?

edit: sorry, I should mention that this will also be in Silverlight, so I'm not sure if Style triggers would work...?

Answer 1

Have a converter like follows,

public sealed class NullToVisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return value == null ? Visibility.Hidden: Visibility.Visible;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Now, bind the property with the Visibility property as well. Like,

<ListBox ItemsSource="{Binding Path=Squad}" 
         Visibility="{Binding Converter={StaticResource nullToVisibilityConverter}, 
                              Path=Squad}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <CheckBox Content="{Binding}" />
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>