title: Regions already registered error on navigation
body: <p>I have a TabControl region in Shell.xaml:</p>
  
  <pre><code>&lt;TabControl Name="TabRegionControl" prism:RegionManager.RegionName="TabRegion" /&gt;
  </code></pre>
  
  <p>The user can click a button to open a new tab, which calls:</p>
  
  <pre><code>RegionManager.RequestNavigate("TabRegion", new Uri("Search?X=1", UriKind.Relative));
  </code></pre>
  
  <p>The new tab is created in the tab control and displays the view. The view contains multiple sub regions (and a view for each of those regions). This works so far. When the user clicks the button again, I get the error saying that the regions are already registered.</p>
  
  <p>I know this is happening because the regions cannot be registered again in the same region manager. I've read that scoped regions can be used to resolve this. As best as I can figure out, I replace the RequestNavigate above with this to create a scoped RegionManager:</p>
  
  <pre><code>SearchViewModel svm = new SearchViewModel();
  IRegion detailsRegion = _regionManager.Regions["TabRegion"];
  SearchView view = new SearchView(svm);
  IRegionManager scopedRegionManager = detailsRegion.Add(view, null, true);
  svm.ScopedRegionManager = scopedRegionManager;
  svm.LoadViews();
  </code></pre>
  
  <p>I believe I have to manually load the views into my sub regions in the method LoadViews(), but the sub regions are not displaying. </p>
  
  <p>Here is how they are defined in Search.xaml:</p>
  
  <pre><code>&lt;ContentControl Background="White" Grid.Row="0"  Grid.Column="0"        
  Regions:RegionManager.RegionName="SubRegion1"
  HorizontalAlignment="Stretch"
  VerticalAlignment="Stretch"
  HorizontalContentAlignment="Stretch"
  VerticalContentAlignment="Stretch"  /&gt;
  </code></pre>
  
  <p>As a starting point, the scopedRegionManager does not seem to have any of my sub regions in it's region collection.</p>
  
  <p><em>edit</em></p>
  
  <p>I am now seeing the sub regions in the region collection of the scoped region manager. The sub views are still not displaying, here is how I am trying to load the sub views inside the LoadViews method, which might be completely off course:</p>
  
  <pre><code>ViewModelSub1 vm = new ViewModelSub1();
  IRegion detailsRegion = _regionManager.Regions["RegionSub1"];
  SubView1 sView = new SubView1(vm);
  IRegionManager detailsRegionManager = detailsRegion.Add(sView, null, false);
  detailsRegion.Activate(wsView);
  </code></pre>
  
  <p>I'm new to WPF and MVVM. Any assistance or pointers in the right direction would be greatly appreciated as I'm utterly lost.</p>
  
  <p>Thanks.</p>