View

  <AbsoluteLayout>
        <SearchBar Text="{Binding SearchText}" AbsoluteLayout.LayoutFlags="WidthProportional" AbsoluteLayout.LayoutBounds="0, 0, 1, 60" IsEnabled="{Binding IsNotBusy}"/>
        <ActivityIndicator AbsoluteLayout.LayoutFlags="PositionProportional" AbsoluteLayout.LayoutBounds="0.5, 0.5, 40, 40" Color="Lime" IsVisible="{Binding IsBusy}" IsRunning="{Binding IsBusy}"/>
  </AbsoluteLayout>