title: Xamarin Form: How to apply NamedSize.Medium to OnIdiom element
body: <p>I can change the font size by passing values to OnIdiom Element for different device. But how do I pass FontSize Medium to the OnIdiom in xaml, what is the TypeArguments to passed into.</p>
  
  <pre><code>&lt;Style x:Name="normalFont"&gt;
      &lt;Setter Property="FontSize"&gt;
          &lt;Setter.Value&gt;
          &lt;OnIdiom.Phone&gt;
          &lt;OnPlatform x:TypeArguments="x:Double" iOS="Small" Android="Small" /&gt;
              &lt;/OnIdiom.Phone&gt;
              &lt;OnIdiom.Tablet&gt;
                  &lt;OnPlatform x:TypeArguments="x:Double" iOS="Medium" Android="Medium" /&gt;
              &lt;/OnIdiom.Tablet&gt;
          &lt;/Setter.Value&gt;
      &lt;/Setter&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>I know it won't be double what type should I put.</p>