title: Change List View Header and Group Header Vertical Order
body: <p>Using xamarin forms.
  I have list view contains header and group header like below.</p>
  
  <pre><code>      &lt;ListView x:Name="Groups" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
          SeparatorVisibility="Default" RowHeight="100" HasUnevenRows="True" IsGroupingEnabled="True" Header=""&gt;
                  &lt;ListView.GroupHeaderTemplate&gt;
                      &lt;DataTemplate&gt;
                          &lt;TextCell Height="50"  Text="{Binding GroupName}" TextColor="White" /&gt;
                      &lt;/DataTemplate&gt;
                  &lt;/ListView.GroupHeaderTemplate&gt;
  
                  &lt;ListView.Header&gt;
  
                  &lt;Grid BackgroundColor="#941a24" Margin="0,10,0,0"&gt;
                          &lt;Grid.ColumnDefinitions&gt;
                              &lt;ColumnDefinition Width="*"/&gt;
                              &lt;ColumnDefinition Width="*"/&gt;
                          &lt;/Grid.ColumnDefinitions&gt;
                          &lt;Label Grid.Column="0" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" TextColor="White" x:Name="Order" /&gt;
                          &lt;Label Grid.Column="1" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" TextColor="White" x:Name="Name"/&gt;
                 &lt;/Grid&gt;
  
                  &lt;/ListView.Header&gt;
  
  
                  &lt;ListView.ItemTemplate&gt;
                      &lt;DataTemplate&gt;
                          &lt;ViewCell&gt;
                              &lt;ViewCell.View&gt;
                                 //items
                              &lt;/ViewCell.View&gt;
                          &lt;/ViewCell&gt;
                      &lt;/DataTemplate&gt;
                  &lt;/ListView.ItemTemplate&gt;
              &lt;/ListView&gt;
  </code></pre>
  
  <p>What is happen is the header of the List View appears Vertically Above the Group Header but I want to show the group header above the header (without changing the list view Binding object) such that every time the group header appears the List view header appears below.</p>