How to select static text with LINQ query?

I have a listbox and I want its ItemsSource to be all the items of an ObservableCollection + an additional static text such as "All Items."

Right now I just have something similar to:

listbox1.ItemsSo开发者_StackOverflow社区urce = from Car c in Cars
                       select c.Model

I know I could just manually add the text to the listbox, but I want it to be part of the query because the linq query is bound using the Obtics library (so the UI updates reactively). I am not too familiar with linq queries outside the basics, so does anyone know if this is possible? Thanks

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You can use the Union() operator to add more objects into your selected set.

string[] additionalItems = {"All Items"};

listbox1.ItemsSource = (from Car c in Cars
                       select c.Model)
                       .Union(additionalItems);