public override void OnResume() { base.OnResume(); viewsHelper.ViewEnabledPredicates( WizardActivity.ButtonNext, new List <KeyValuePair <int, Predicate <string> > > { new KeyValuePair <int, Predicate <string> >(Resource.Id.edtLastName, ValidateHasContent), new KeyValuePair <int, Predicate <string> >(Resource.Id.edtFirstName, ValidateHasContent), new KeyValuePair <int, Predicate <string> >(Resource.Id.edtPhone, ValidateHasContent), new KeyValuePair <int, Predicate <string> >(Resource.Id.edtPhone, PhoneNumberLooksOk) }); viewsHelper.SetViewEnabledState(WizardActivity.ButtonNext); }