控制器不存在:app\index\controller\Case

        try {
            $instance = Loader::controller(
                $controller,
                $config['url_controller_layer'],
                $config['controller_suffix'],
                $config['empty_controller']
            );
        } catch (ClassNotFoundException $e) {
            throw new HttpException(404, 'controller not exists:' . $e->getClass());
        }

        // 获取当前操作名
        $action = $actionName . $config['action_suffix'];

        $vars = [];
        if (is_callable([$instance, $action])) {
            // 执行操作方法
            $call = [$instance, $action];