title: Border not lining up on a TextBlock
body: <p>I am working on a chat program, and I would like to have a single line separate every line of text.  </p>
  
  <p>Here is the XAML I am using:</p>
  
  <pre><code>&lt;ScrollViewer Grid.Row="0" Name="ScrollBar"&gt;
      &lt;ListView HorizontalContentAlignment="Stretch"
                BorderThickness="0"
                IsTabStop="False"
                Name="AllItems"
                Background="#E4E4E4"
                ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                PreviewMouseWheel="AllItems_PreviewMouseWheel"
                ItemsSource="{Binding Messages}"&gt;
  
          &lt;ListView.ItemTemplate&gt;
              &lt;DataTemplate&gt;
                  &lt;Border BorderBrush="Black"
                          BorderThickness="0, 1, 0, 0"&gt;
                      &lt;TextBlock
                              FontSize="16"
                              TextWrapping="Wrap"
                              FontFamily="Arial"
                              Margin="0"
                              Initialized="ChatLine_Initialized"
                              VerticalAlignment="Center" /&gt;
                  &lt;/Border&gt;
              &lt;/DataTemplate&gt;
          &lt;/ListView.ItemTemplate&gt;
      &lt;/ListView&gt;
  &lt;/ScrollViewer&gt;
  </code></pre>
  
  <p>I'm also setting the background of each line in alternating colors (this is an event handler for TextBlock's Initialize event):</p>
  
  <pre><code>static int s_curr;
  
  void ChatLine_Initialized(object sender, EventArgs e)
  {
      int curr = Interlocked.Increment(ref s_curr);
      if ((curr % 2) == 0)
          ((TextBlock)sender).Background = (SolidColorBrush)(new BrushConverter().ConvertFrom("#C8C8C8"));
      else
          ((TextBlock)sender).Background = (SolidColorBrush)(new BrushConverter().ConvertFrom("#E4E4E4"));
  }
  </code></pre>
  
  <p>The problem I'm running into is that the darker lines do not fill down to the border.<br>
  For example, here is how it renders:</p>
  
  <p><img src="https://i.stack.imgur.com/HEyVq.png" alt="Lines"></p>
  
  <p>How do I get the darker background to fill down to the border line?</p>