title: Slider_ValueChanged Does not work properly
body: <p>I'm Trying to bind a <code>TextBlock</code> to a <code>Slider</code> Value. </p>
  
  <p>So what I did is to set the text value of the <code>TextBlock</code> to the value of the slider with the <code>ValueChanged</code> event. Here is my <code>XAML</code>:</p>
  
  <pre><code>&lt;TextBlock Name="PartyNumber" Text="1"  
             FontSize="40" FontFamily="Calibri" 
             Width="100" FontWeight="Bold" Foreground="Green"/&gt;
  &lt;Slider Name="PartyNumberSlider" Grid.Row="5" 
          Width="340" Style="{StaticResource SliderStyle1}" 
          Height="100" Maximum="12" 
          Minimum="1" Value="1" 
          ValueChanged="PartyNumberSlider_ValueChanged" /&gt;
  </code></pre>
  
  <p>My code behind is like this:   </p>
  
  <pre><code>private void PartyNumberSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs&lt;double&gt; e)
  {
      PartyNumber.Text = PartyNumberSlider.Value.ToString();
  }
  </code></pre>
  
  <p>When I launch the app, the <code>ValueChanged</code> event fires upon initialisation, and it handles and <code>NullReferenceExeption</code>.</p>
  
  <p>I do not even get to change the slider's value.</p>
  
  <p>So any idea on what I'm doing wrong?</p>