title: to show a dialog: what is the difference of use messageBox and create a view and a view model in MVVM pattern?
body: <p>I have always read that is not a good solution to use in the view model the messageBox to show a dialog when it is used the MVVM pattern.</p>
  
  <p>Show I think that the other solution is create a view and a view model that is create in my main view model and related the view and the view model of the dialog. Additionally, I need to create a class that is passed from the main view model to the dialog view model that is returned as result of the dialog.</p>
  
  <p>But really the second way is better? what is it the difference? because in both cases I need to wait until the result of the dialog.</p>
  
  <p>Or both of t he solutions are a bad option?</p>
  
  <p>Thanks.</p>