title: MVVM: How to call method on view from view model?
body: <p>I am quite new to MVVM, so sorry for probably simple question. However, I can not understand which mechanism from MVVVM (I am using MVVMLight if that is of any consequence) to use in order to program the simple following scenario:</p>
  
  <p>I have textbox TB, where user can fill in URL. Than I have a button B and webview WV. If user clicks on button, the app should take the text from TB and display it in the WV. </p>
  
  <p>I knwo that I can create a property in viewmodel and bound it to TB.Text. I understand probably also that I should create command which will be boudn from button B, but what should I do in the command. How I can call WV.navigate(url), when I do not have reference to WV. Should this be solved by something, which I did not grasp correctly like behaviours? What is the best way to do this?</p>