title: UWP CommandBar as resource
body: <p>I got a <code>CommandBar</code> i'd like to use for all my pages within the app.
  When creating a new command bar using the 'New' button in the properties window and converting the new value to a resource using 'Convert to New Resource' (the resource is placed in a resource dictionary) VS creates
  the following xaml:</p>
  
  <pre><code>&lt;Page.BottomAppBar&gt;
      &lt;StaticResource ResourceKey="BottomBar" /&gt;
  &lt;/Page.BottomAppBar&gt;
  </code></pre>
  
  <p>Resource dict.:</p>
  
  <pre><code>&lt;CommandBar x:Key="BottomBar" /&gt;
  </code></pre>
  
  <p>Now when launching the application an unhandled exception with the message 'The parameter is incorrect' is thrown (inner exception: 'Value does not fall within the expected range'). Is that intended behaviour or is there a workaround (except for using a style)?</p>