...bind to another control? For example, in XAML:
<ContentPage .....>
<StackLayout>
<Switch x:Name="swExample" />
<Entry x:Name="entryFoo" IsEnabled="{Binding ElementName=swExample, Path=IsToggled}" />
</StackLayout>
</ContentPage>
In WPF programming that would work. In Xamarin.Forms, it does not. Is there a way to do this?