How do I add a property to my Xamarin page that I can use in a default style?
<p>I have added a <code>BarTextColor</code> property to my custom Xamarin page, like so:</p>

<pre><code>    public static readonly BindableProperty BarTextColorProperty = BindableProperty.Create("BarTextColor", typeof(Color), typeof(MyCustomPage), Color.Default);

    public Color BarTextColor
    {
        get { return (Color)GetValue(BarTextColorProperty); }
        set { SetValue(BarTextColorProperty, value); UpdateInnerViews(); }
    }
</code></pre>

<p>But when I try to set a global style in my App.xaml like so:</p>

<pre><code>    &lt;Style TargetType="myapp:MyCustomPage"&gt;
        &lt;Setter Property="BarTextColor" Value="{StaticResource BarTextColor}"/&gt;
    &lt;/Style&gt;
</code></pre>

<p>I get this error:</p>

<blockquote>
  <p>Property 'BarTextColor' must be a DependencyProperty to be set with a Setter</p>
</blockquote>

<p>and this:</p>

<blockquote>
  <p>The property "BarTextColor" is not a DependencyProperty. To be used in
  markup, non-attached properties must be exposed on the target type
  with an accessible instance property "BarTextColor". For attached
  properties, the declaring type must provide static "GetBarTextColor" 
  and "SetBarTextColor" methods.</p>
</blockquote>

<p>What's going wrong?  The Xamarin source on github all uses <code>BindableProperty</code> not <code>DependencyProperty</code>, so why can't I?</p>

<p>(I'm using Visual Studio Community 2013 with Xamarin 2.3.1, in case it matters)</p>