WPF Button内容基于DataContext设置

I'm working with WPF and MVVM pattern, I have a simple view which consists of a Button, which should display one thing or another depending on a property of the DataContext (viewmodel) I've used datatriggers and datatemplates to try make this work, but for some reason the binding is not evaluating (or i'm doing something wrong).I'm working with WPF and MVVM pattern, I have a