src/Controller.php
protected function setIndex(string $url = ''): void
    {
        if (empty($url)) {
            $_SESSION['_INDEX_URL'] = $this->request->url();
        } else {
            $_SESSION['_INDEX_URL'] = $url;
        }
    }
protected function setIndex(string $url = ''): void
    {
        if (empty($url)) {
            $_SESSION['_INDEX_URL'] = $this->request->url();
        } else {
            $_SESSION['_INDEX_URL'] = $url;
        }
    }
设置返回列表页的URL,以后可以用getIndex获取此URL
@param string $url 要设置的URL