The problem statement: I am tired of thinking how to show a simple message box or user prompt and act based on the response in Model-View-View-Model (MVVM). Common approaches: - It's ok, let's just do this one thing from ViewModel and mock this out for unit testing - Design my own dialog, then what to do from there - Can I write something in view code behind, ah yes, that seems to be the only way out, as anyway MVVM is still not matured... - and what not? I am pretty much one among the few frustrated...