Question

I have an item controller which I bind to ObservableCollection<User>.
I ran into an issue where when there is only one user I would like to show a different ItemTemplate (just the Rating for example – and use default for everything else) and if there are more I would like to let people edit a bit more about them – combo box etc.

I though that probably there is a way of using converter for this, however I’m not sure how I can use converter to pick either one or another. So far I have managed to write a converter to hide/show two separate ItemControls dependable on Count of ObservableCollection<User> property. However, I don’t think this is the best way of solving this problem.

Are there better ways of solving this?

Answer 1

You need only one ItemsControl with template selection:

 <ItemsControl ItemsSource="{Binding Users}" ItemTemplate="{Binding Users.Count, Converter={StaticResource UserTemplateSelector}"/>

where

    public class UserTemplateSelector : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            int userCount = (int) value;
            if (userCount == 1)
            {
                return (DataTemplate) Application.Current.Resources["SingleUserTemplate"]; //SingleUserTemplate should be created e.g. in App.xaml
            }

            return (DataTemplate)Application.Current.Resources["MultipleUserTemplate"]; //MultipleUserTemplate should be created e.g. in App.xaml
        }

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