title: Xamarin Forms watch ViewModel property from .xaml.cs class
body: <p>As the title suggests, on Xamarin Forms, I am trying to watch from a View when a property on the ViewModel changes.</p>
  
  <p>This is my ViewModel class</p>
  
  <pre><code>public class RegisterViewModel : INotifyPropertyChanged
  {
      public event PropertyChangedEventHandler PropertyChanged;
      public bool AutomaticVerificationDone { get; set; }
  
      public ICommand AutomaticVerification
      {
          get
          {
              return new Command(async () =&gt;
              {
                  AutomaticVerificationDone = true;
                  PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("AutomaticVerificationDone"));
              });
          }
      }
  }
  </code></pre>
  
  <p>This is my Register.xaml.cs class</p>
  
  <pre><code>public partial class Register : ContentPage
  {
      public static readonly BindableProperty AutomaticVerificationDoneProperty = BindableProperty.Create(nameof(AutomaticVerificationDone), typeof(bool), typeof(Register), false);
      public bool AutomaticVerificationDone
      {
          get { return (bool)GetValue(AutomaticVerificationDoneProperty); }
          set
          {
              SetValue(AutomaticVerificationDoneProperty, value);
              if (value)
                  accessButton.Opacity = 1;
              else
                  accessButton.Opacity = 0.8f;
  
          }
      }
  
      public Register()
      {
          InitializeComponent();
          NavigationPage.SetHasNavigationBar(this, false);
          this.BindingContext = new RegisterViewModel();
      }
  }
  </code></pre>
  
  <p>Doing in this way nothing happens.
  What am I missing?</p>