private async void ListaDeCursos() { try { Cursos = await Matricula.ListaDeCursos(); Pk_Curso.ItemsSource = Cursos; } catch (JsonException ex) { DependencyService.Get <IMessageError>().LongAlert(ex.Message); } catch (HttpRequestException ex) { DependencyService.Get <IMessageError>().LongAlert(ex.Message); } catch (Exception ex) { DependencyService.Get <IMessageError>().LongAlert("Verifica a sua conexão de internet"); } finally { } }