title: Xaml and DataGrid and Databinding Issues
body: <p>Given a view-model with public writeable properties SelectedItem and SelectedIndex, it would be nice to be able to do the following:</p>
  
  <pre><code>&lt;DataGrid SelectedItem="{Binding SelectedItem}" ...
  </code></pre>
  
  <p>Then the view-model would easily know what item is currently selected. Unfortunately, this does not work (Notification occurs once, at start-up). Why?</p>
  
  <p>The following does consistently notify the view-model,</p>
  
  <pre><code>&lt;DataGrid SelectedIndex="{Binding SelectedIndex}" ...
  </code></pre>
  
  <p>Unfortunately, the "index" value is actually relatively to the filtered and sorted ICollectView which wraps the underlying collection (Why). ICollectionView does not have a index property my initial attempts at accessing it directly triggered a stack-overflow (no pun intended).</p>
  
  <p>I suspect there are good reasons for these "gotchas" in the current Xaml implementation. It may even be due to the fact that I am using an F#/Xaml template.</p>