core/Route.php
public static function getPath(string $app = null)
    {
        if ($app == null) {
            $app = self::get('app');
        }
        if (empty($app)) {
            return null;
        }
        $data = isset(self::$routeMap[$app]) ? self::$routeMap[$app] : [];
        if (empty($data['path'])) {
            return null;
        }
        $path = Utils::path(ROOT_DIR, $data['path']);
        return $path;
    }
public static function getPath(string $app = null)
    {
        if ($app == null) {
            $app = self::get('app');
        }
        if (empty($app)) {
            return null;
        }
        $data = isset(self::$routeMap[$app]) ? self::$routeMap[$app] : [];
        if (empty($data['path'])) {
            return null;
        }
        $path = Utils::path(ROOT_DIR, $data['path']);
        return $path;
    }
获取当前应用目录
@param string|null $app
@return null|string