title: Xamarin.Forms Vertical StackLayout in ListView displays only one (first) Child
body: <pre><code>&lt;ListView 
      ItemsSource="{Binding Messages}"
      Grid.ColumnSpan="2"
      HeightRequest="100"&gt;
      &lt;ListView.ItemTemplate&gt;
          &lt;DataTemplate&gt;
              &lt;ViewCell&gt;
                  &lt;ViewCell.View&gt;
                      &lt;StackLayout&gt;
                          &lt;Label
                              Text="{Binding When}"
                              XAlign="Center"/&gt;
                          &lt;StackLayout
                              BackgroundColor="Gray"
                              Orientation="Vertical"
                              VerticalOptions="Center"&gt;
                              &lt;Label
                                  Text="{Binding Message}"
                                  XAlign="Start"/&gt;
                              &lt;Label
                                  Text="{Binding Sender}"
                                  XAlign="Start"
                                  TextColor="Red"/&gt;
  
                          &lt;/StackLayout&gt;
                      &lt;/StackLayout&gt;
                   &lt;/ViewCell.View&gt;
              &lt;/ViewCell&gt;
          &lt;/DataTemplate&gt;
      &lt;/ListView.ItemTemplate&gt;
  &lt;/ListView&gt;
  </code></pre>
  
  <p>I am rendering a custom ListView in Xamarin.Forms application. The <code>StackLayout</code> which contains two <code>Label</code>s (to which "Message" and "Sender" has been bound), currently displays only one child. With the code above, it displays only "Message". If I change code to be </p>
  
  <pre><code>&lt;StackLayout
        BackgroundColor="Gray"
        Orientation="Vertical"
        VerticalOptions="Center"&gt;
        &lt;Label
           Text="{Binding Sender}"
           XAlign="Start"
           TextColor="Red"/&gt;
        &lt;Label
            Text="{Binding Message}"
            XAlign="Start"/&gt;
    &lt;/StackLayout&gt;
  </code></pre>
  
  <p>it displays only sender. In short it is displaying only first child. What have I done wrong here ?</p>