title: How can I add a background image to the bottom tab bar in a Xamarin Forms Shell application with an iOS renderer?
body: <p>I know how to do this in the top header area: </p>
  
  <pre><code>    protected override IShellSectionRenderer CreateShellSectionRenderer(ShellSection shellSection)
      {
          var renderer = base.CreateShellSectionRenderer(shellSection);
          if (renderer != null)
          {
              (renderer as ShellSectionRenderer).NavigationBar.SetBackgroundImage(UIImage.FromFile("LaunchIcon.png"), UIBarMetrics.Default);
  
          }
          return renderer;
      }
  </code></pre>
  
  <p>but not in the bottom navigation tab area.    </p>
  
  <p>Would appreciate any advice from anyone who has tried to customise the bottom area background.</p>