Xamarin.Forms.Core 1.0.0.0 1.1.0.0 1.2.0.0 1.3.0.0 1.4.0.0 1.5.0.0 2.0.0.0 Contravariant System.Delegate System.Boolean To be added. To be added. To be added. Strongly-typed delegate for BindableProperty.ValidateValue. To be added. To be added.