title: Activating views in regions in Prism
body: <p>I have problem that I don't seem to be able to solve. I have a created a test project, using MEF and Prism4. I've created a test project where I have 2 views and each of them register themselves inside a region, and also a button in another region. When the button is clicked, I want the view of change to the correct view. The code I think is wrong is below, anyone have any ideas what I am doing wrong here ?</p>
  
  <pre><code>    public void Initialize()
      {
          regionManager.RegisterViewWithRegion(RegionNames.MainRegion, typeof(Views.Module1View));
  
          Button button = new Button() { Content = "Module1" };
          button.Click += (o, i) =&gt;
          {
              var region = this.regionManager.Regions[RegionNames.MainRegion];
              if (region != null)
              {
                  region.Activate(typeof(Views.Module1View));
              }
          };
  
          regionManager.AddToRegion(RegionNames.NavigationRegion, button);
      }
  </code></pre>
  
  <p>I get the following error ...</p>
  
  <pre><code>The region does not contain the specified view.
  Parameter name: view
  </code></pre>