WPF: Trigger for ListBoxItem.IsSelected not working for Background property

Question

I try to change the Background property for my ListBoxItems using triggers in the ItemContainerStyle of my ListBox as fol

Answer 1

A little bit of reflecting on the Aero-style offers us an explanation to why this simple trigger-setting doesn't work.

The ListBoxItem has a ControlTemplate with triggers that takes precedence over our trigger. At least this seems to be true for a MultiTrigger. I´ve managed to override the simple trigger of Selected=true but for the multitrigger I had to make my own ControlTemplate.

This is the template from the Aero style that shows the problematic MultiTrigger:

Hope it clears things up a little bit. I can't fathom why they´ve overcomplicated the style this much.