What is the last event to fire when loading a new WPF/C# window?

Question

I am trying to load a preferences window for my application and I would like the apply button to initially be disabled, then when a preference is updated, the apply button g

Answer 1

I just did kind of the same thing behaviorly in a systray WPF app.

However, I didn't do it using event handling. I simply bound the Enabled property of my button to a property in my ViewModel, and had the property updated whenever I needed the behavior.