title: Uwp Grouped GridView with WrapGrid
body: <p>I'm developing an UWP app and I'm trying to align horizontally my items in each gridview groups </p>
  
  <p>I have this :</p>
  
  <pre><code>GROUP 1
  
  Data 1 | Data 2 | Data 3
  
  Data 1 | Data 2 | Data 3
  
  Data 1 | Data 2 | Data 3
  
  GROUP 2
  
  Data 1 | Data 2 | Data 3
  
  Data 1 | Data 2 | Data 3
  </code></pre>
  
  <p>and I want this :</p>
  
  <pre><code>GROUP 1
  
  ______________________________Data 1 | Data 2 | Data 3
  
  ______________________________Data 1 | Data 2 | Data 3
  
  ______________________________Data 1 | Data 2 | Data 3
  
  GROUP 2
  
  ______________________________Data 1 | Data 2 | Data 3
  
  ______________________________Data 1 | Data 2 | Data 3
  </code></pre>
  
  <p>I order to align my items I use a WrapGrid.
  I also tried with a non grouped gridview and my code works fine.</p>
  
  <pre><code>&lt;GridView Grid.Column="0" ItemsSource="{Binding Source={StaticResource GroupBycodeFamille}}" ItemTemplate="{StaticResource DataTempateCatalogue}"&gt;
  &lt;GridView.GroupStyle&gt;
  &lt;GroupStyle&gt;
  &lt;GroupStyle.HeaderTemplate&gt;
  &lt;DataTemplate x:DataType="viewModels:GroupInfoList"&gt;
  &lt;TextBlock Text="{x:Bind Key}" Style="{ThemeResource TitleTextBlockStyle}"/&gt;
  &lt;/DataTemplate&gt;
  &lt;/GroupStyle.HeaderTemplate&gt;
  &lt;/GroupStyle&gt;
  &lt;/GridView.GroupStyle&gt;
  &lt;GridView.ItemsPanel&gt;
  &lt;ItemsPanelTemplate&gt;
  &lt;WrapGrid Orientation="Horizontal" HorizontalAlignment="Center"/&gt;
  &lt;/ItemsPanelTemplate&gt;
  &lt;/GridView.ItemsPanel&gt;
  &lt;/GridView&gt;
  </code></pre>