Xamarin.Forms DerivedPage.xaml/cs from BasePage, Binding ViewModel in XAML.

AboutPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<derived:BasePage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="....AboutPage"
             xmlns:local="clr-namespace:...;assembly=..."
             xmlns:derived="clr-namespace:....View;assembly=..."
             BindingContext="{x:Static local:App.AboutViewModel}"
             Title="About">
  <StackLayout Orientation="Vertical" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
    <Label Text="{Binding Detail}"/>
    <Label Text="{Binding TofS}">
      <Label.GestureRecognizers>
        <TapGestureRecognizer Command="{Binding TofSCommand}" />
      </Label.GestureRecognizers>
    </Label>
    </Label>
  </StackLayout>
</derived:BasePage>

AboutPage.xaml.cs

namespace ... {
    public partial class AboutPage : BasePage {
        public AboutPage() {
            InitializeComponent();
            ((AboutViewModel)BindingContext).set(this); // AboutViewModel is public static in the App.cs for the XAML reference below.
        }
    }
}