title: Bug displaying characters of Segoe MDL2 Assets after converting them to string
body: <p>I'm using xaml universal project and have problem displaying some characters of font Segoe MDL2 Assets after converting to string in code behind. Please see images and anyone with ideia how to fix this:</p>
  
  <p><a href="https://i.stack.imgur.com/C49ql.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/C49ql.jpg" alt="icons from font Segoe MDL2 Assets"></a></p>
  
  <p>Xaml:</p>
  
  <pre><code>&lt;converters:MyTypeConv x:Key="myTypeConv" /&gt;
  
  &lt;dSrc:clsLstElem x:Key="lstCmdAnsw"&gt;
          &lt;dSrc:clsElem iAuto="0" /&gt;
          &lt;dSrc:clsElem iAuto="1" /&gt;
          &lt;dSrc:clsElem iAuto="2" /&gt;
  &lt;/dSrc:clsLstElem&gt;
  </code></pre>
  
  <p>Xaml usage:</p>
  
  <pre><code> &lt;Border CornerRadius="5" BorderBrush="Black" BorderThickness="1"&gt;
      &lt;ItemsControl ItemsSource="{StaticResource lstCmdAnsw}"&gt;
          &lt;ItemsControl.ItemsPanel&gt;
              &lt;ItemsPanelTemplate&gt;
                  &lt;ItemsWrapGrid Orientation="Horizontal"/&gt;
              &lt;/ItemsPanelTemplate&gt;
          &lt;/ItemsControl.ItemsPanel&gt;
          &lt;ItemsControl.ItemTemplate&gt;
              &lt;DataTemplate&gt;
                  &lt;Button
                   Content="{Binding iAuto, Mode=OneWay, Converter={StaticResource myTypeConv}}" 
                   FontFamily="Segoe MDL2 Assets" 
                   FontSize="{ThemeResource ContentControlFontSize}" /&gt;
              &lt;/DataTemplate&gt;
          &lt;/ItemsControl.ItemTemplate&gt;
      &lt;/ItemsControl&gt;
  &lt;/Border&gt;
  </code></pre>
  
  <p>Code behind:</p>
  
  <pre><code>     public class MyTypeConv : Windows.UI.Xaml.Data.IValueConverter
       {
          public object Convert(object value, Type targetType,
                                    object parameter, string language)
          {
                      string s = string.Empty;
                      if (value != null)
                      {
                          switch ((int)value)
                          {
                              case 0:
                                  s = "\uE81D";
                                  break;
                              case 1:
                                  s = "\uE927;";
                                  break;
                              case 2:
                                  s = "\uE916;;";
                                  break;
                          }
                      }
                      return s;
           }
  }
  </code></pre>