title: Dynamic Listview Resizing
body: <p>i want to dynamically adjust the width of my List View/Items.
  So when the user changes the screen size of the App, the Listview automatically adjust to the perfect size. 
  At the moment i`m using adaptiv triggers, but there i have to specifically define values for each possible size i want to support.</p>
  
  <pre><code>&lt;VisualStateManager.VisualStateGroups&gt;
   &lt;VisualStateGroup&gt;
    &lt;VisualState&gt;
     &lt;VisualState.StateTriggers&gt;
      &lt;AdaptiveTrigger MinWindowWidth="1000"&gt;&lt;/AdaptiveTrigger&gt;
     &lt;/VisualState.StateTriggers&gt;
     &lt;VisualState.Setters&gt;
       &lt;Setter Target="textBlockOne.(RelativePanel.Width)" Value="130" /&gt;
     &lt;/VisualState.Setters&gt;
  </code></pre>
  
  <p>Every other element i can access and manipulate in the codebehind.
  Even the ListView Header is accessible.
  So it would be very nice if someone has a solution for accessing the values in the ListView DataTemplate.</p>
  
  <p>Something like this would be awesome:</p>
  
  <pre><code>&lt;ListView x:Name="testList"&gt;
   &lt;ListView.Header&gt;
    &lt;StackPanel x:Name="TestListHeaderStackPanel"&gt;
   &lt;/ListView.Header&gt;
   &lt;ListView.ItemTemplate&gt;
    &lt;DataTemplate x:Name="DataTemplatedata"&gt;
     &lt;Grid x:Name="GridTest"&gt;
      .....
     &lt;/Grid&gt;
    &lt;/DataTemplate&gt;
   &lt;ListView.ItemTemplate&gt;
  &lt;ListView&gt;
  
      private void OnPageSizeChanged(object sender, SizeChangedEventArgs args)
      {
       GridTest.ColumnDefinitions[1].Width=20;
      }
  </code></pre>