Question

Hey Guys (and girls if any 🙂

I needed a different list box selection policy than the one provided by default with WPF listboxes, i.e. beeing able to have an extended selection withou any modifier key.

No problem on that, here is what I did :

class EnhancedCcyPairListBox : ListBox
{

    protected override DependencyObject GetContainerForItemOverride()
    {
        return new CcyPairListBoxItem();
    }

}

internal class CcyPairListBoxItem : ListBoxItem
{
    protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
    {
        IsSelected = !IsSelected;

        e.Handled = true;
    }
}

I can’t tell if it’s the best way to do, but it seems to work exactly as I expected.

Except that… by doing so, I have lost the defaults ListBoxItem style I had before. How can I tell to my derived classes to keep their default style ?

Thank you very much !

Answer 1

Add this above the EnhancedCcyPairListBox declaration

    [StyleTypedProperty(Property = "ItemContainerStyle", StyleTargetType = typeof(CcyPairListBoxItem))]

Edit

Add this to the static constructor of CcyPairListBoxItem”

            DefaultStyleKeyProperty.OverrideMetadata(
            typeof(CcyPairListBoxItem), new FrameworkPropertyMetadata(typeof(CcyPairListBoxItem)));

and in Themes/Generic.xaml add

<Style TargetType="{x:Type CcyPairListBoxItem}"
       BasedOn="{StaticResource {x:Type ListBoxItem}}"/>