Aug 08, 2012
You shouldn't have a click even handler in your code behind. Use a Command (maybe with a commandHelper) to handle this.
The functionality of the click event is handled in the method of the Command in the ViewModel. If you want to use a messagebox you use a viewmanager (with an interface and IoC) and use a method on the viewmanager to handle the messagebox.
You can also have a look at Caliburn micro.