title: Communicate two view models in WPF MVVM
body: <p>I am developing a WPF application and I have some problems to communicate one view model with another.</p>
  
  <p>I have:</p>
  
  <ol>
  <li>MainViewModel </li>
  <li>ChildViewModel1 </li>
  <li>ChildViewModel2</li>
  </ol>
  
  <p>Every time a property changes in MainViewModel, ChildViewModel1 and ChildViewModel2 should get notified.</p>
  
  <p>Can anyone suggest a workaround?</p>
  
  <p>EDIT:
  I am thinking in a solution descrided MVVM Light (<a href="http://simplemvvmtoolkit.codeplex.com/SourceControl/changeset/view/23821#313594.">http://simplemvvmtoolkit.codeplex.com/SourceControl/changeset/view/23821#313594.</a>), that is implementing a message bus. Is it the right approach?</p>