18-snack-bar-04-action-03.dart

  Widget _snackAction() => SnackBar(
        content: Text(
          "Test the action in the SnackBar.",
          style: TextStyle(
            color: TEXT_BLACK,
            fontSize: 20,
          ),
          textAlign: TextAlign.center,
        ),
        action: SnackBarAction(
          label: "I Know!",
          textColor: Colors.white,
          disabledTextColor: TEXT_BLACK_LIGHT,
          onPressed: () {
            print("I know you are testing the action in the SnackBar!");
          },
        ),
        backgroundColor: BLUE_LIGHT,
      );