View source for UI/Shell

{{ElementSpec
 | title=Shell
 | kind=Navigation Host
 | ms_url=https://learn.microsoft.com/dotnet/maui/fundamentals/shell/?view=net-maui-9.0
 | introduced=MAUI 6.0 (.NET 6)
 | deprecated=No
 | notes=Top-level app container providing routing, flyout, and tabs.
 | props=
  <tr><td>Items</td><td>?</td><td></td><td>FlyoutItem/TabBar hierarchy</td></tr>
  <tr><td>Title</td><td>?</td><td></td><td>Window title</td></tr>
  <tr><td>FlyoutBehavior</td><td>?</td><td></td><td>Disabled/Locked/Flyout</td></tr>
  <tr><td>NavBarIsVisible</td><td>?</td><td></td><td>Show/hide navigation bar</td></tr>
  <tr><td>SearchHandler</td><td>?</td><td></td><td>Integrated search UI</td></tr>
  <tr><td>TabBarTitleColor</td><td>?</td><td></td><td>Platform-specific</td></tr>
  <tr><td>BackgroundColor</td><td>?</td><td></td><td>Shell background</td></tr>
}}