在页面预渲染挂钩typo3中获取请求uri

Question

我需要在页面加载之前获取请求的URL。请在下面找到我的代码

ext_localconf.php

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_pagerenderer.php']['render-preProcess'][\my\class\hook::class]
        = \my\class\hook::class . '->execute';

挂钩

  $objectManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\Extbase\\Object\\ObjectManager');
  $request = $objectManager->get('TYPO3\\CMS\\Extbase\\Mvc\\Web\\Request');
  \TYPO3\CMS\Extbase\Utility\DebuggerUtility::var_dump($request->getRequestUri);

它返回空值？如何在这里获取数据？