title: Tab data lost on selected item changed MVVM
body: <p>I have been trying to do this for ages and having no joy whatsoever.</p>
  
  <p>I have a ribbon window of the following hierarchy:</p>
  
  <ul>
  <li>MainWindow
  <ul>
  <li>MainContent (Tab Control)
  <ul>
  <li>TabContainerViewModel
  <ul>
  <li>ViewModelBase</li>
  </ul></li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>View model base has an ObservableCollection of tabs type ViewModelBase. The Tab Control itself is binding fine to these, displaying appropriate view models. I have 2 problems however, I want a "NotepadView" (Of type viewmodelbase) to be replicated numerous times (one view many view models).</p>
  
  <p>At the minute, I have 4 views (NotePadViewModelx where x is 1-4) with corresponding viewmodels, this is because each view had the same text per tab. Now I have individual views per tab.</p>
  
  <p>When I type into tab 1 and switch to tab 2, I lose what I typed in tab one when I click back.</p>
  
  <p>Could somebody help to provide me with a solution to these problems?</p>
  
  <ul>
  <li>One NotepadView for multiple instances of the ViewModel</li>
  <li>Keeping information when tabs change</li>
  </ul>
  
  <p>Many thanks in advance.</p>