public async void LoginExist() { try { var username = Utilty.GetSecureStorageValueFor(Utilty.UserName); var password = Utilty.GetSecureStorageValueFor(Utilty.Password); response1 = await api.LoginUserAsync(username.Result, password.Result); if (response1.Status) { Application.Current.MainPage = new NavigationPage(new BarcodePage()); } else { Application.Current.MainPage = new NavigationPage(new LoginPage()); } } catch (Exception ex) { // Possible that device doesn't support secure storage on device. } }