public static function createInstance() { if (self::$instance == null) { $pluginFile = IWeb::$app->getBasePath() . 'plugins/collect/collect.php'; if (is_file($pluginFile)) { include_once $pluginFile; self::$instance = new collect(); } else { self::$error = '当前版本没有此功能 <a href="http://www.aircheng.com/buy" target="_blank">立即购买</a>'; } } return self::$instance; }