How to open a new window using MVVM Light Toolkit

Question

I am using MVVM Light toolkit in my WPF application. I would like to know what is the best approach for opening a new window from an existing window. I have got this M

Answer 1

Unless I am missing the point here - if I were to use the code behind, then why not directly implement button_click event and open the second view?

What Bugnion seems to be suggesting is view1 -> button click -> relay command -> viewmodel1 -> message -> view1 -> view1.cs -> open view 2.

You are going to sacrifice testability anyhow by writing code-behind, so why take such a long route?